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Saturday, June 06, 2020

Wirelurker For OSX, iOS (Part I) And Windows (Part II) Samples

PART II

Wirelurker for Windows (WinLurker)

Research: Palo Alto Claud Xiao: Wirelurker for Windows

Sample credit: Claud Xiao

PART I

Research: Palo Alto Claud Xiao WIRELURKER: A New Era in iOS and OS X Malware

Palo Alto |Claud Xiao - blog post Wirelurker

Wirelurker Detector https://github.com/PaloAltoNetworks-BD/WireLurkerDetector

Sample credit: Claud Xiao

Download

Download Part I
Download Part II

Email me if you need the password

List of files

List of hashes

Part II

s+«sìÜ 3.4.1.dmg 925cc497f207ec4dbcf8198a1b785dbd

apps.ipa 54d27da968c05d463ad3168285ec6097
WhatsAppMessenger 2.11.7.exe eca91fa7e7350a4d2880d341866adf35
使用说明.txt 3506a0c0199ed747b699ade765c0d0f8
libxml2.dll c86bebc3d50d7964378c15b27b1c2caa
libiconv-2_.dll 9c8170dc4a33631881120a467dc3e8f7
msvcr100.dll bf38660a9125935658cfa3e53fdc7d65
libz_.dll bd3d1f0a3eff8c4dd1e993f57185be75
mfc100u.dll f841f32ad816dbf130f10d86fab99b1a

zlib1.dll c7d4d685a0af2a09cbc21cb474358595

│ apps.ipa
│ σ╛«σìÜ 3.4.1.dmg
│
└───WhatsAppMessenger 2.11.7
libiconv-2_.dll
libxml2.dll
libz_.dll
mfc100u.dll
msvcr100.dll
WhatsAppMessenger 2.11.7.exe
zlib1.dll
使用说明.txt

Part I

BikeBaron 15e8728b410bfffde8d54651a6efd162
CleanApp c9841e34da270d94b35ae3f724160d5e
com.apple.MailServiceAgentHelper dca13b4ff64bcd6876c13bbb4a22f450
com.apple.appstore.PluginHelper c4264b9607a68de8b9bbbe30436f5f28
com.apple.appstore.plughelper.plist 94a933c449948514a3ce634663f9ccf8
com.apple.globalupdate.plist f92640bed6078075b508c9ffaa7f0a78
com.apple.globalupdate.plist f92640bed6078075b508c9ffaa7f0a78
com.apple.itunesupdate.plist 83317c311caa225b17ac14d3d504387d
com.apple.machook_damon.plist 6507f0c41663f6d08f497ab41893d8d9
com.apple.machook_damon.plist 6507f0c41663f6d08f497ab41893d8d9
com.apple.MailServiceAgentHelper.plist e6e6a7845b4e00806da7d5e264eed72b
com.apple.periodic-dd-mm-yy.plist bda470f4568dae8cb12344a346a181d9
com.apple.systemkeychain-helper.plist fd7b1215f03ed1221065ee4508d41de3
com.apple.watchproc.plist af772d9cca45a13ca323f90e7d874c2c
FontMap1.cfg 204b4836a9944d0f19d6df8af3c009d5
foundation 0ff51cd5fe0f88f02213d6612b007a45
globalupdate 9037cf29ed485dae11e22955724a00e7
globalupdate 9037cf29ed485dae11e22955724a00e7
itunesupdate a8dfbd54da805d3c52afc521ab7b354b
libcrypto.1.0.0.dylib 4c5384d667215098badb4e850890127b
libcrypto.1.0.0.dylib 3b533eeb80ee14191893e9a73c017445
libiconv.2.dylib 94f9882f5db1883e7295b44c440eb44c
libiconv.2.dylib fac8ef9dabdb92806ea9b1fde43ad746
libimobiledevice.4.dylib c596adb32c143430240abbf5aff02bc0
libimobiledevice.4.dylib 5b0412e19ec0af5ce375b8ab5a0bc5db
libiodb.dylib bc3aa0142fb15ea65de7833d65a70e36
liblzma.5.dylib 5bdfd2a20123e0893ef59bd813b24105
liblzma.5.dylib 9ebf9c0d25e418c8d0bed2a335aac8bf
libplist.2.dylib 903cbde833c91b197283698b2400fc9b
libplist.2.dylib 109a09389abef9a9388de08f7021b4cf
libssl.1.0.0.dylib 49b937c9ff30a68a0f663828be7ea704
libssl.1.0.0.dylib ab09435c0358b102a5d08f34aae3c244
libusbmuxd.2.dylib e8e0663c7c9d843e0030b15e59eb6f52
libusbmuxd.2.dylib 9efb552097cf4a408ea3bab4aa2bc957
libxml2.2.dylib 34f14463f28d11bd0299f0d7a3985718
libxml2.2.dylib 95506f9240efb416443fcd6d82a024b9
libz.1.dylib 28ef588ba7919f751ae40719cf5cffc6
libz.1.dylib f2b19c7a58e303f0a159a44d08c6df63
libzip.2.dylib 2a42736c8eae3a4915bced2c6df50397
machook 5b43df4fac4cac52412126a6c604853c
machook ecb429951985837513fdf854e49d0682
periodicdate aa6fe189baa355a65e6aafac1e765f41
pphelper 2b79534f22a89f73d4bb45848659b59b
sfbase.dylib bc3aa0142fb15ea65de7833d65a70e36

sfbase.dylib bc3aa0142fb15ea65de7833d65a70e36
sfbase_v4000.dylib 582fcd682f0f520e95af1d0713639864
sfbase_v4001.dylib e40de392c613cd2f9e1e93c6ffd05246
start e3a61139735301b866d8d109d715f102
start e3a61139735301b866d8d109d715f102
start.sh 3fa4e5fec53dfc9fc88ced651aa858c6
stty5.11.pl dea26a823839b1b3a810d5e731d76aa2
stty5.11.pl dea26a823839b1b3a810d5e731d76aa2
systemkeychain-helper e03402006332a6e17c36e569178d2097
watch.sh 358c48414219fdbbbbcff90c97295dff
WatchProc a72fdbacfd5be14631437d0ab21ff960
7b9e685e89b8c7e11f554b05cdd6819a 7b9e685e89b8c7e11f554b05cdd6819a
update 93658b52b0f538c4f3e17fdf3860778c
start.sh 9adfd4344092826ca39bbc441a9eb96f

File listing

├───databases

│ foundation

│

├───dropped

│ ├───version_A

│ │ │ com.apple.globalupdate.plist

│ │ │ com.apple.machook_damon.plist

│ │ │ globalupdate

│ │ │ machook

│ │ │ sfbase.dylib

│ │ │ watch.sh

│ │ │

│ │ ├───dylib

│ │ │ libcrypto.1.0.0.dylib

│ │ │ libiconv.2.dylib

│ │ │ libimobiledevice.4.dylib

│ │ │ liblzma.5.dylib

│ │ │ libplist.2.dylib

│ │ │ libssl.1.0.0.dylib

│ │ │ libusbmuxd.2.dylib

│ │ │ libxml2.2.dylib

│ │ │ libz.1.dylib

│ │ │

│ │ ├───log

│ │ └───update

│ ├───version_B

│ │ com.apple.globalupdate.plist

│ │ com.apple.itunesupdate.plist

│ │ com.apple.machook_damon.plist

│ │ com.apple.watchproc.plist

│ │ globalupdate

│ │ itunesupdate

│ │ machook

│ │ start

│ │ WatchProc

│ │

│ └───version_C

│ │ com.apple.appstore.plughelper.plist

│ │ com.apple.appstore.PluginHelper

│ │ com.apple.MailServiceAgentHelper

│ │ com.apple.MailServiceAgentHelper.plist

│ │ com.apple.periodic-dd-mm-yy.plist

│ │ com.apple.systemkeychain-helper.plist

│ │ periodicdate

│ │ stty5.11.pl

│ │ systemkeychain-helper

│ │

│ └───manpath.d

│ libcrypto.1.0.0.dylib

│ libiconv.2.dylib

│ libimobiledevice.4.dylib

│ libiodb.dylib

│ liblzma.5.dylib

│ libplist.2.dylib

│ libssl.1.0.0.dylib

│ libusbmuxd.2.dylib

│ libxml2.2.dylib

│ libz.1.dylib

│ libzip.2.dylib

│

├───iOS

│ sfbase.dylib

│ sfbase_v4000.dylib

│ sfbase_v4001.dylib

│ start

│ stty5.11.pl

│

├───IPAs

│ 7b9e685e89b8c7e11f554b05cdd6819a

│ pphelper

│

├───original

│ BikeBaron

│ CleanApp

│ FontMap1.cfg

│ start.sh

│

└───update

start.sh

update

One Reason Why InfoSec Sucked In The Past 20 Years - The "Security Tips" Myth

From time to time, I get disappointed how much effort and money is put into securing computers, networks, mobile phones, ... and yet in 2016 here we are, where not much has changed on the defensive side. There are many things I personally blame for this situation, and one of them is the security tips.

The goal of these security tips is that if the average user follows these easy to remember rules, their computer will be safe. Unfortunately, by the time people integrate these rules into their daily life, these rules either become outdated, or these rules were so oversimplified that it was never true in the first place. Some of these security tips might sound ridiculous to people in InfoSec nowadays, but this is exactly what people still remember because we told them so for years.

PDF is safe to open

This is an oldie. I think this started at the time of macro viruses. Still, people think opening a PDF from an untrusted source is safer than opening a Word file. For details why this is not true, check: https://www.cvedetails.com/vulnerability-list/vendor_id-53/product_id-497/Adobe-Acrobat-Reader.html

On an unrelated note, people still believe PDF is integrity protected because the content cannot be changed (compared to a Word document).

Image stolen from Kaspersky

Java is secure

One of the best ones. Oracle started marketing Java as a safe language, where buffer overflows, format strings and pointer-based vulnerabilities are gone. Unfortunately, they forgot to tell the world that instead of "unsafe programs developed by others" they installed their unsafe program on 3 billion devices.

Stay away from rogue websites and you will be safe

This is a very common belief I hear from average people. "I only visit some trusted news sites and social media, I never visit those shady sites." I have some bad news. At the time of malvertising and infected websites, you don't have to visit those shady sites anymore to get infected.

Don't use open WiFi

I have a very long explanation of why this makes no sense, see here. Actually, the whole recommendation makes no sense as people will connect to public WiFis, no matter what we (InfoSec) recommend.

The password policy nightmare

Actually, this topic has been covered by myself in two blog posts, see here and here. Long story short: use a password manager and 2-factor authentication wherever possible. Let the password manager choose the password for you. And last but not least, corporate password policy sux.

Sites with a padlock are safe

We tell people for years that the communication with HTTPS sites are safe, and you can be sure it is HTTPS by finding a randomly changing padlock icon somewhere next to the URL. What people hear is that sites with padlocks are safe. Whatever that means. The same goes for WiFi - a network with a padlock is safe.

Use Linux, it is free from malware

For years people told to Windows users that only if they would use Linux they won't have so much malware. Thanks to Android, now everyone in the world can enjoy malware on his/her Linux machine.

OSX is free from malware

It is true that there is significantly less malware on OSX than on Windows, but this is an "economical" question rather than a "security" one. The more people use OSX, the better target it will become. Some people even believe they are safe from phishing because they are using a Mac!

Updated AV + firewall makes me 100% safe

There is no such thing as 100% safe, and unfortunately, nowadays most malware is written for PROFIT, which means it can bypass these basic protections for days (or weeks, months, years). The more proactive protection is built into the product, the better!

How to backup data

Although this is one of the most important security tips which is not followed by people, my problem here is not the backup data advise, but how we as a community failed to provide easy to use ways to do that. Now that crypto-ransomware is a real threat to every Windows (and some OSX) users, even those people who have backups on their NAS can find their backups lost. The only hope is that at least OSX has Time Machine which is not targeted yet, and the only backup solution which really works.

The worst part is that we even created NAS devices which can be infected via worms ...

Disconnect your computer from the Internet when not used

There is no need to comment on this. Whoever recommends things like that, clearly has a problem.

Use (free) VPN to protect your anonimity

First of all. There is no such thing as free service. If it is free, you are the service. On another hand, a non-free VPN can introduce new vulnerablities, and they won't protect your anonymity. It replaces one ISP with another (your VPN provider). Even TOR cannot guarantee anonymity by itself, and VPNs are much worse.

The corporate "security tips" myth

"Luckily" these toxic security tips have infected the enterprise environment as well, not just the home users.

Use robots.txt to hide secret information on public websites

It is 2016 and somehow web developers still believe in this nonsense. And this is why this is usually the first to check on a website for penetration testers or attackers.

My password policy is safer than ever

As previously discussed, passwords are bad. Very bad. And they will stick with us for decades ...

Use WAF, IDS, IPS, Nextgen APT detection hibber-gibber and you will be safe

Companies should invest more in people and less into magic blinking devices.

Instead of shipping computers with bloatware, ship computers with exploit protection software

Teach people how to use a password safe

Teach people how to use 2FA

Teach people how to use common-sense

Conclusion

Computer security is complex, hard and the risks change every year. Is this our fault? Probably. But these kinds of security tips won't help us save the world.

Friday, June 05, 2020

BeEF: Browser Exploitation Framework

"BeEF is the browser exploitation framework. A professional tool to demonstrate the real-time impact of XSS browser vulnerabilities. Development has focused on creating a modular structure making new module development a trivial process with the intelligence residing within BeEF. Current modules include the first public Inter-protocol Exploit, a traditional browser overflow exploit, port scanning, keylogging, clipboard theft and more." read more...

Website: http://www.bindshell.net/tools/beef

More articles

Chapter 1To 5 HTML

Contents

About

................................................................................................................................................................................... 1

Chapter 1: Getting started with HTML

................................................................................................................ 2

Section 1.1: Hello World 2

Chapter 2: Doctypes

.................................................................................................................................................... 4

Section 2.1: Adding the Doctype 4

Section 2.2: HTML 5 Doctype 4

Chapter 3: Headings

.................................................................................................................................................... 5

Section 3.1: Using Headings 5

Chapter 4: Paragraphs

.............................................................................................................................................. 6

Section 4.1: HTML Paragraphs

Chapter 5: Text Formatting

..................................................................................................................................... 6

..................................................................................................................................... 7

Section 5.1: Highlighting 7

Section 5.2: Bold, Italic, and Underline 7

Section 5.3: Abbreviation 8

Section 5.4: Inserted, Deleted, or Stricken 8

Section 5.5: Superscript and Subscript 8

Chapter 1: Getting started with HTML

Version Speciﬁcation Release Date

1.0 N/A 1994-01-01

2.0 RFC 1866

1995-11-24

3.2 W3C: HTML 3.2 Speciﬁcation

1997-01-14

4.0 W3C: HTML 4.0 Speciﬁcation

1998-04-24

4.01 W3C: HTML 4.01 Speciﬁcation

1999-12-24

5 WHATWG: HTML Living Standard

2014-10-28

5.1 W3C: HTML 5.1 Speciﬁcation

2016-11-01

Section 1.1: Hello World

Introduction

HTML (Hypertext Markup Language) uses a markup system composed of elements which represent speciﬁc content. Markup means that with HTML you declare what is presented to a viewer, not how it is presented. Visual representations are deﬁned by Cascading Style Sheets (CSS) and realized by browsers. Still existing elements that allow for such, like e.g. font, "are entirely obsolete, and must not be used by authors"[1].

HTML is sometimes called a programming language but it has no logic, so is a markup language. HTML tags provide semantic meaning and machine-readability to the content in the page.

An element usually consists of an opening tag (<element_name>), a closing tag (</element_name>), which contain the element's name surrounded by angle brackets, and the content in between:

<element_name>...content...</element_name>

There are some HTML elements that don't have a closing tag or any contents. These are called void elements. Void elements include <img>, <meta>, <link> and <input>.

Element names can be thought of as descriptive keywords for the content they contain, such as video, audio, table, footer.

A HTML page may consist of potentially hundreds of elements which are then read by a web browser, interpreted and rendered into human readable or audible content on the screen.

For this document it is important to note the diﬀerence between elements and tags:

Elements: video, audio, table, footer

Tags: <video>, <audio>, <table>, <footer>, </html>, </body>

Element insight

Let's break down a tag...

The <p> tag represents a common paragraph.

Elements commonly have an opening tag and a closing tag. The opening tag contains the element's name in angle brackets (<p>). The closing tag is identical to the opening tag with the addition of a forward slash (/) between the opening bracket and the element's name (</p>).

Content can then go between these two tags: <p>This is a simple paragraph.</p>.

Creating a simple page

The following HTML example creates a simple "Hello World" web page.

HTML ﬁles can be created using any text editor. The ﬁles must be saved with a .html or .htm[2] extension in order to be recognized as HTML ﬁles.

Once created, this ﬁle can be opened in any web browser.

Simple page break down

These are the tags used in the example:

Tag Meaning

<!DOCTYPE> Deﬁnes the HTML version used in the document. In this case it is HTML5.

See the doctypes topic for more information.

Opens the page. No markup should come after the closing tag (</html>). The lang attribute declares

<html>

<head>

<meta>

the primary language of the page using the ISO language codes (en for English). See the Content Language topic for more information.

Opens the head section, which does not appear in the main browser window but mainly contains information about the HTML document, called metadata. It can also contain imports from external stylesheets and scripts. The closing tag is </head>.

Gives the browser some metadata about the document. The charset attribute declares the character encoding. Modern HTML documents should always use UTF-8, even though it is not a requirement. In HTML, the <meta> tag does not require a closing tag.

See the Meta topic for more information.

<title> The title of the page. Text written between this opening and the closing tag (</title>) will be displayed on the tab of the page or in the title bar of the browser.

<body> Opens the part of the document displayed to users, i.e. all the visible or audible content of a page. No content should be added after the closing tag </body>.

<h1> A level 1 heading for the page.

See headings for more information.

<p> Represents a common paragraph of text.

1. ↑ HTML5, 11.2 Non-conforming features

2. ↑ .htm is inherited from the legacy DOS three character ﬁle extension limit.

Chapter 2: Doctypes

Doctypes - short for 'document type' - help browsers to understand the version of HTML the document is written in for better interpretability. Doctype declarations are not HTML tags and belong at the very top of a document. This topic explains the structure and declaration of various doctypes in HTML.

Section 2.1: Adding the Doctype

The <!DOCTYPE> declaration should always be included at the top of the HTML document, before the <html> tag.

Version ≥ 5

See HTML 5 Doctype for details on the HTML 5 Doctype.

Section 2.2: HTML 5 Doctype

HTML5 is not based on SGML (Standard Generalized Markup Language), and therefore does not require a reference to a DTD (Document Type Deﬁnition).

HTML 5 Doctype declaration:

Case Insensitivity

Per the W3.org HTML 5 DOCTYPE Spec:

A DOCTYPE must consist of the following components, in this order:

1. A string that is an ASCII case-insensitive match for the string "<!DOCTYPE".

therefore the following DOCTYPEs are also valid:

This SO article discusses the topic extensively: Uppercase or lowercase doctype?

Chapter 3: Headings

HTML provides not only plain paragraph tags, but six separate header tags to indicate headings of various sizes and thicknesses. Enumerated as heading 1 through heading 6, heading 1 has the largest and thickest text while heading 6 is the smallest and thinnest, down to the paragraph level. This topic details proper usage of these tags.

Section 3.1: Using Headings

Headings can be used to describe the topic they precede and they are deﬁned with the <h1> to <h6> tags. Headings support all the global attributes.

<h1> deﬁnes the most important heading.

<h6> deﬁnes the least important heading.

Deﬁning a heading:

Correct structure matters

Search engines and other user agents usually index page content based on heading elements, for example to create a table of contents, so using the correct structure for headings is important.

In general, an article should have one h1 element for the main title followed by h2 subtitles – going down a layer if necessary. If there are h1 elements on a higher level they shoudn't be used to describe any lower level content.

Example document (extra intendation to illustrate hierarchy):

Chapter 4: Paragraphs

Column Column

<p> Deﬁnes a paragraph

<br> Inserts a single line break

<pre> Deﬁnes pre-formatted text

Paragraphs are the most basic HTML element. This topic explains and demonstrates the usage of the paragraph element in HTML.

Section 4.1: HTML Paragraphs

The HTML <p> element deﬁnes a paragraph:

Display-

You cannot be sure how HTML will be displayed.

Large or small screens, and resized windows will create diﬀerent results.

With HTML, you cannot change the output by adding extra spaces or extra lines in your HTML code. The browser will remove any extra spaces and extra lines when the page is displayed:

Chapter 5: Text Formatting

While most HTML tags are used to create elements, HTML also provides in-text formatting tags to apply speciﬁc text-related styles to portions of text. This topic includes examples of HTML text formatting such as highlighting, bolding, underlining, subscript, and stricken text

Section 5.1: Highlighting

The <mark> element is new in HTML5 and is used to mark or highlight text in a document "due to its relevance in another context".1

The most common example would be in the results of a search were the user has entered a search query and results are shown highlighting the desired query.

Output:

A common standard formatting is black text on a yellow background, but this can be changed with CSS.

Section 5.2: Bold, Italic, and Underline

Bold Text

To bold text, use the <strong> or <b> tags:

What's the diﬀerence? Semantics. <strong> is used to indicate that the text is fundamentally or semantically important to the surrounding text, while <b> indicates no such importance and simply represents text that should be bolded.

If you were to use <b> a text-to-speech program would not say the word(s) any diﬀerently than any of the other words around it - you are simply drawing attention to them without adding any additional importance. By using

<strong>, though, the same program would want to speak those word(s) with a diﬀerent tone of voice to convey that the text is important in some way.

Italic Text

To italicize text, use the <em> or <i> tags:

What's the diﬀerence? Semantics. <em> is used to indicate that the text should have extra emphasis that should be stressed, while <i> simply represents text which should be set oﬀ from the normal text around it.

For example, if you wanted to stress the action inside a sentence, one might do so by emphasizing it in italics via

<em>: "Would you just submit the edit already?"

But if you were identifying a book or newspaper that you would normally italicize stylistically, you would simply use

<i>: "I was forced to read Romeo and Juliet in high school.

Underlined Text

While the <u> element itself was deprecated in HTMl 4, it was reintroduced with alternate semantic meaning in HTML 5 - to represent an unarticulated, non-textual annotation. You might use such a rendering to indicate misspelled text on the page, or for a Chinese proper name mark.

Section 5.3: Abbreviation

To mark some expression as an abbreviation, use <abbr> tag:

If present, the title attribute is used to present the full description of such abbreviation.

Section 5.4: Inserted, Deleted, or Stricken

To mark text as inserted, use the <ins> tag:

To mark text as deleted, use the <del> tag:

To strike through text, use the <s> tag:

Section 5.5: Superscript and Subscript

To oﬀset text either upward or downward you can use the tags <sup> and <sub>. To create superscript:

To create subscript:

@EVERYTHINGNT

Thursday, June 04, 2020

Vsftpd Backdoor - Ekoparty Prectf - Amn3S1A Team

It's a 32bits elf binary of some version of vsftpd, where it have been added a backdoor, they don't specify is an authentication backdoor, a special command or other stuff.

I started looking for something weird on the authentication routines, but I didn't found anything significant in a brief period of time, so I decided to do a bindiff, that was the key for locating the backdoor quickly. I do a quick diff of the strings with the command "strings bin | sort -u" and "vimdiff" and noticed that the backdoored binary has the symbol "execl" which is weird because is a call for executing elfs, don't needed for a ftp service, and weird that the compiled binary doesn't has that symbol.

Looking the xrefs of "execl" on IDA I found that code that is a clear backdoor, it create a socket, bind a port and duplicate the stdin, stdout and stderr to the socket and use the execl:

There are one xrefs to this function, the function that decides when trigger that is that kind of systems equations decision:

The backdoor was not on the authentication, it was a special command to trigger the backdoor, which is obfuscated on that systems equation, it was no needed to use a z3 equation solver because is a simple one and I did it by hand.

The equation:

cmd[0] = 69

cmd[1] = 78

cmd[1] + cmd[2] = 154

cmd[2] + cmd[3] = 202

cmd[3] + cmd[4] = 241

cmd[4] + cmd[5] = 233

cmd[5] + cmd[6] = 217

cmd[6] + cmd[7] = 218

cmd[7] + cmd[8] = 228

cmd[8] + cmd[9] = 212

cmd[9] + cmd[10] = 195

cmd[10] + cmd[11] = 195

cmd[11] + cmd[12] = 201

cmd[12] + cmd[13] = 207

cmd[13] + cmd[14] = 203

cmd[14] + cmd[15] = 215

cmd[15] + cmd[16] = 235

cmd[16] + cmd[17] = 242

The solution:

cmd[0] = 69

cmd[1] = 75

cmd[2] = 79

cmd[3] = 123

cmd[4] = 118

cmd[5] = 115

cmd[6] = 102

cmd[7] = 116

cmd[8] = 112

cmd[9] = 100

cmd[10] = 95

cmd[11] = 100

cmd[12] = 101

cmd[13] = 106

cmd[14] = 97

cmd[15] = 118

cmd[16] = 117

cmd[17] = 125

The flag:

EKO{vsftpd_dejavu}

The binary:
https://ctf.ekoparty.org/static/pre-ekoparty/backdoor

TLS-Attacker V2.2 And The ROBOT Attack

We found out that many TLS implementations are still vulnerable to different variations of a 19-year old Bleichenbacher's attack. Since Hanno argued to have an attack name, we called it ROBOT: https://robotattack.org

Given the new attack variants, we released a new version of TLS-Attacker 2.2, which covers our vulnerabilities.

Bleichenbacher's attack from 1998

In 1998, Daniel Bleichenbacher discovered that the error messages given by SSL servers for errors in the PKCS #1 1.5 padding allow an adversary to execute an adaptive-chosen ciphertext attack. This attack also belongs to the category of padding oracle attacks. By performing the attack, the adversary exploits different responses returned by the server that decrypts the requests and validates the PKCS#1 1.5 padding. Given such a server, the attacker can use it as an oracle and decrypt ciphertexts.

We refer to one of our previous blog posts for more details.

OK, so what is new in our research?

In our research we performed scans of several well-known hosts and found out many of them are vulnerable to different forms of the attack. In the original paper, an oracle was constructed from a server that responded with different TLS alert messages. In 2014, further side-channels like timings were exploited. However, all the previous studies have considered mostly open source implementations. Only a few vulnerabilities have been found.

In our scans we could identify more than seven vulnerable products and open source software implementations, including F5, Radware, Cisco, Erlang, Bouncy Castle, or WolfSSL. We identified new side-channels triggered by incomplete protocol flows or TCP socket states.

For example, some F5 products would respond to a malformed ciphertext located in the ClientKeyExchange message with a TLS alert 40 (handshake failure) but allow connections to timeout if the decryption was successful. We could observe this behaviour only when sending incomplete TLS handshakes missing ChangeCipherSpec and Finished messages.

See our paper for more interesting results.

Release of TLS-Attacker 2.2

These new findings motivated us to implement the complete detection of Bleichenbacher attacks in our TLS-Attacker. Before our research, TLS-Attacker had implemented a basic Bleichenbacher attack evaluation with full TLS protocol flows. We extended this evaluation with shortened protocol flows with missing ChangeCipherSpec and Finished messages, and implemented an oracle detection based on TCP timeouts and duplicated TLS alerts. In addition, Robert (@ic0ns) added many fixes and merged features like replay attacks on 0-RTT in TLS 1.3.

You can find the newest version release here: https://github.com/RUB-NDS/TLS-Attacker/releases/tag/v2.2

TLS-Attacker allows you to automatically send differently formatted PKCS#1 encrypted messages and observe the server behavior:

$ java -jar Attacks.jar bleichenbacher -connect [host]:[port]

In case the server responds with different error messages, it is most likely vulnerable. The following example provides an example of a vulnerable server detection output:

14:12:42 [main] CONSOLE attacks.impl.Attacker - A server is considered vulnerable to this attack if it responds differently to the test vectors.
14:12:42 [main] CONSOLE attacks.impl.Attacker - A server is considered secure if it always responds the same way.
14:12:49 [main] CONSOLE attacks.impl.Attacker - Found a difference in responses in the Complete TLS protocol flow with CCS and Finished messages.
14:12:49 [main] CONSOLE attacks.impl.Attacker - The server seems to respond with different record contents.
14:12:49 [main] INFO  attacks.Main - Vulnerable:true

In this case TLS-Attacker identified that sending different PKCS#1 messages results in different server responses (the record contents are different).

Wednesday, June 03, 2020

Linux Command Line Hackery Series: Part 1

In this concise article we will learn some basics of how to use Linux Command line, so lets get started.

Requirements:

1. An open Terminal in your Linux Box. I'm using Kali Linux 2.0
or you can check out this amazing website Webminal

Command: ls
Syntax:    ls [flag(s)]
Function: ls is short for list. ls command is used to list the contents of a directory these contents include files, folders, and links. ls has many optional flags as well, some of them are described below
Flags: -a this flag is used to view hidden files that is those files whose names are preceded   by a '.'(dot)
-l this flag is used to view file permissions, owner of the file, group of the owner, the file size, the modification date, and the filename. We'll talk more about it in later articles.

Command: mkdir
Syntax:   mkdir dirname
Function: mkdir is used to create a directory (or a folder) with the name which is followed by the command

now lets create a directory in our current directory named as myfiles, how would you do that?

mkdir myfiles

which command should we use in order to verify that the directory has been created in our current folder?

ls

this will list all the files and directories in our current folder. Do you see myfiles directory listed?

Command: cd
Syntax:   cd path/to/directory
Function: cd is short for change directory. It is used to navigate directories, or to make it clear it does the same thing as what double clicking on a folder do except it doesn't show you contents of the directory :(. In order to navigate or visit another directory we need to provide it's ABSOLUTE-PATH or RELATIVE-PATH you heard that, didn't ya?

Paths are of two types relative path or absolute path (also called full-path). Relative as the name suggests is relative to the current directory, so if you have to navigate to a folder within the current directory you'll just simply type cd directory_name. But what if you have to navigate to a directory which is the parent of current directory? Well it's easy just type cd .. (yes double dots, you noticed that .. and . thing when you typed ls -a, didn't you?). The double dots mean the directory above current directory (i,e the parent directory) and a single dot means the current directory (i,e the directory that I'm currently in). Now if you have to navigate two directories above current directory using relative path navigation you'll type

cd ../..

here .. means previous directory and another .. after slash (/) means the previous directory of the previous directory sounds confusing..!

The Absolute Path means full path to the file or folder which starts from root directory. Say I want to navigate to my home folder using absolute path, then I'll type:

cd /home/user

where user is the username
Now think of navigating to the myfiles folder from your home directory using the absolute path, it will be something like this:

cd /home/user/myfiles

Exercise: Create a directory project1 inside your home directory and inside the project1 directory create a file and a directory named index.html and css respectively. Then navigate to the css directory and create a style.css file inside it. At last navigate out of the css directory to home both using the relative and absolute path mechanisms.

[Trick: To get quickly out of any directory to your home directory type cd ~ [press Enter] or simply cd [press Enter]]

Command: touch
Syntax: touch filename
Function: touch is a nifty little function used to create an empty file (actually it's used to change access time of a file but everyone has got bad habits :P ). You can create any type of empty file with the touch command. If you are a bit curious about touch read the manual page of the touch command using the man touch command.

Now lets create a few files inside of our myfiles directory

touch file1 file2 file3

The above command creates three empty files in our current directory named file1, file2, and file3.
How will you verify that it has indeed created these three files in your current directory? I won't answer this time.

Command: echo
Syntax: echo Hacker manufacturing under process
Function: echo is used to display a line of text. By default echo displays a line of text on the terminal which is the standard output device (stdout for short). However we can redirect the output of an echo command to a file using > (the greater than symbol).
Now if we have to echo a line of text to a file, say file1 in our myfiles directory, we will type:

echo This is file1 > file1

The above command will echo the text "This is file1" to file1.

Command: cat
Syntax: cat filename [anotherfilename...]
Function: cat stands for concatenate (not that puny little creature in your house). The main function of cat is to concatenate files and display them on your terminal (or in geeky terms stdout). But its also used to display the contents of a file on your terminal.

Let's display the contents of file1 in the myfiles directory that we echoed to it using the echo command, for that we'll type:

cat file1

Awesome I can see on black screen contents of my file (what if your terminals background is white?), looks like I'm becoming a hacker. In case you don't see it then I suggest you should give up the thought of becoming a hacker. Just kidding you might have missed a step or two from the above steps that we performed.

Now lets say that we want to add another line of text to our file using the echo command should we use the same greater than (>) symbol? No, if we want to add another line (which in geeky terms is to append a line) to our file using the echo command we have to use >> (two greater than symbols) like this:

echo Another line of text >> file1

now to check the contents of file1 we'll type:

cat file1

OK we wrote two lines inside of the file1.
Does it mean we have to add three greater than symbols to write third line? Oh! I didn't thought you'd be such a genius.

A single greater than symbol (>) means redirect the output of the preceding command to a file specified after the > symbol. If the file exists then overwrite everything that's in it with the new contents and if the file does not exist then create one and write to it the output of the preceding command. So if you had typed

echo Another line of text > file1

it would have overwritten the contents of the file1 with "Another line of text" and the line "This is file1" would no longer be present in the file.

Two greater than symbols (>>) mean that append (remember the geeky term?) the output of the previous command to the end of file specified after >>. Now if you want to add another line of text to file1, you won't use >>> rather you'll use >> like this:

echo Third line in file1 >> file1

This is it for today. But don't worry we'll learn more things soon.

More articles

Saturday, June 06, 2020

Related links

PDF is safe to open

Java is secure

Stay away from rogue websites and you will be safe

Don't use open WiFi

The password policy nightmare

Sites with a padlock are safe

Use Linux, it is free from malware

OSX is free from malware

Updated AV + firewall makes me 100% safe

How to backup data

Disconnect your computer from the Internet when not used

Use (free) VPN to protect your anonimity

The corporate "security tips" myth

Use robots.txt to hide secret information on public websites

My password policy is safer than ever

Use WAF, IDS, IPS, Nextgen APT detection hibber-gibber and you will be safe

Conclusion

Related links

Friday, June 05, 2020

Related links

Thursday, June 04, 2020

More articles

Bleichenbacher's attack from 1998

OK, so what is new in our research?

Release of TLS-Attacker 2.2

More articles

Wednesday, June 03, 2020

Requirements:

Cartelera en Aragón Liberal

Contributors

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