Monday 17 October 2016

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The Threat Behind an Italian Phishing Campaign


According to Wikipedia (https://en.wikipedia.org/wiki/Phishing) Phishing is the attempt to obtain sensitive information such as usernames, passwords, and credit card details (and sometimes, indirectly,money), often for malicious reasons, by masquerading as a trustworthy entity in an electronic communication

This case is not about Phishing, because this campaign doesn't try to achieve sensitive information, but instead of phishing it is "something else"...

This email has been delivered in one of my mailbox honeypots.

It's very easy to understand that it is a fake email, but even if today the most of the people believe that it is authentic. This is due the fraudster's evil idea to hits the most sensitive part of the mind of every person, the pocket and the money.

This email seems to come from the Italian Agency that praise taxes.

Clicking on the hyperlink "Scarica il Documento", a web page will be showed to the end user.

Here a file named "Documento Numero 00020160830.pdf" will be download

At the first time I didn't pay attention to the phrase "La password per accedere alla fattura è 7604", and I have focused my attention on the file.

I decided to open the document. The icon was a zip icon but by enabling the folder's option "show file extension", the extension was ".pdf"


Well, as I expected it was a zip file, but it asked me a PASSWORD. I was reminded about the password printed in the webpage, I have put it and the file was extracted.





-------------------- STATIC ANALYSIS --------------------


The sample file was packed using NullSoft Software. 
A packer is a special program used to obfuscate the entire file.


Investigating into the sample file, two digital certificates have been discovered.




One of this digital certificate has been revoked.













-------------------- CODE REVERSE ENGINEERING --------------------


The pictures below report a code snippet to show how the malware checks and asks the path of "Temp" directory

...and below is reported the request for "ResourceLocate" directory in order to achieve GUI language.
Into pictures reported below there are strings, like DLL file names, URL and Domain, but also part of command like "[Rename]\r\n"








-------------------- DYNAMIC ANALYSIS --------------------



I have run it on my virtual environment. A process with the same name of the file was executed and another process with a name "xkpgcoc.exe" has been created.




Checking the performance graph is easy to note that only the process "xkpgcoc.exe" was doing  I/O activity on disk."



















At  the end of its task, this was the result:

All data into my virtual environment was encrypted by CTB-Locker. The extension used to encrypt files has been seven random chars. The file name pattern after the encryption is: 
<Original_File_Name>.<Original_Extension_Uppercase>.<Seven_Random_Chars>.

Running this ransomware more than one time, I noted that it changes every time the crypt-extension.
Killing the process"xkpgcoc.exe", the countdown disappear and we can read on desktop background the instructions to pay and recovery files. During the malware execution, no network traffic was generated. This mean that the cryptolocker doesn't comunicate with a C2C Server The public key are generated locally using a specific algorithm.




Instruction is also reported in a TXT file, named "!Decrypt-All-Files-aruugia.txt" and "!Decrypt-All-Files-aruugia.jpg", located within "Documents" directory.

Is useful to note four important things:


  1. The Cryptolocker didn't identify that it wasrunning on a Virtual environment
  2. The Cryptolocker didn't network connections with any C2C server
  3. The countdown was not TRUE
  4. There are not information about how much the user have to pay to recovery files.

Going one step ahead, Tor website has been checked, in order to understand the process that the user have to follow in to recovery files.


Typing the public key into the form, we receive the following webpage.

The payment simulation has been done different weeks after the infection. This demonstrate how the countdown is fake and it is useful only to scared the victim.

The webpage reported above could be reached directly knowing the URL. This mean that the fist page does not made a real check on the public key reported into the desktop background and into the instruction files. 

The only check that the first web page do, is to verify if the key was generated by the algorithm embedded into the cryptolocker. A random Public Key does not works and an an error was reported to the user.
This is a trick to lure the user or a not expert analyst.


It is a CTB-Locker and there is no known way to decrypt files encrypted by it without paying the ransom. (as reported by Kaspersky)

Everyone of Kaspersky and TrendMicro decrypter was tested and no one of them have been able to decrypt the files encrypted with CTB-Locker.



-------------------- FORENSICS ANALYSIS --------------------


Below is reported the changes that this ransomware did into my VM.

----------------------------------
Chiave cancellata (removed keys) :3
----------------------------------
HKU\S-1-5-21-682910469-3081883402-3337175249-1000\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{688d2436-fb66-11e5-8224-08d40c63bf18}\shell
HKU\S-1-5-21-682910469-3081883402-3337175249-1000\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{688d2436-fb66-11e5-8224-08d40c63bf18}\shell\Autoplay
HKU\S-1-5-21-682910469-3081883402-3337175249-1000\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{688d2436-fb66-11e5-8224-08d40c63bf18}\shell\Autoplay\DropTarget

----------------------------------
Chiave aggiunta (added keys):32
----------------------------------
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Logon\{9C691604-1C86-496F-9A97-388265B2C111}
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Tasks\{9C691604-1C86-496F-9A97-388265B2C111}
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Tree\bxymszh
HKLM\SOFTWARE\Wow6432Node\Microsoft\Tracing\xkpgcoc_RASAPI32
HKLM\SOFTWARE\Wow6432Node\Microsoft\Tracing\xkpgcoc_RASMANCS
HKU\S-1-5-21-682910469-3081883402-3337175249-1000\Software\Microsoft\Windows\CurrentVersion\Explorer\ComDlg32\OpenSavePidlMRU\PML
HKU\S-1-5-21-682910469-3081883402-3337175249-1000\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.aruugia
HKU\S-1-5-21-682910469-3081883402-3337175249-1000\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.aruugia\OpenWithList
HKU\S-1-5-21-682910469-3081883402-3337175249-1000\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.PML
HKU\S-1-5-21-682910469-3081883402-3337175249-1000\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.PML\OpenWithList
HKU\S-1-5-21-682910469-3081883402-3337175249-1000\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.PML\OpenWithProgids
HKU\S-1-5-21-682910469-3081883402-3337175249-1000\Software\Microsoft\Windows\CurrentVersion\Explorer\RecentDocs\.PML
HKU\S-1-5-21-682910469-3081883402-3337175249-1000\Software\Microsoft\Windows Photo Viewer
HKU\S-1-5-21-682910469-3081883402-3337175249-1000\Software\Microsoft\Windows Photo Viewer\Viewer
 ...(continue) 

----------------------------------
Valore cancellato (changed values) :3
----------------------------------
HKU\S-1-5-21-682910469-3081883402-3337175249-1000\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{688d2436-fb66-11e5-8224-08d40c63bf18}\shell\: "None"
HKU\S-1-5-21-682910469-3081883402-3337175249-1000\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{688d2436-fb66-11e5-8224-08d40c63bf18}\shell\Autoplay\MUIVerb: "@shell32.dll,-8507"
HKU\S-1-5-21-682910469-3081883402-3337175249-1000\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{688d2436-fb66-11e5-8224-08d40c63bf18}\shell\Autoplay\DropTarget\CLSID: "{F26A669A-BCBB-4E37-ABF9-7325DA15F931}"

----------------------------------
Valore aggiunto (added values) :134
----------------------------------
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Tasks\{9C691604-1C86-496F-9A97-388265B2C111}\Path: "\bxymszh"
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Tasks\{9C691604-1C86-496F-9A97-388265B2C111}\Hash:  9C B1 E8 C3 45 CA 30 48 28 22 AF C4 95 DE F4 83 97 E3 11 86 A1 0B 33 AC 0A C1 AF 69 13 65 02 8E
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Tasks\{9C691604-1C86-496F-9A97-388265B2C111}\Triggers:  15 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 FF FF FF FF FF FF FF FF 58 21 41 00 48 48 48 48 93 EB 00 1F 48 48 48 48 00 48 48 48 48 48 48 48 00 48 48 48 48 48 48 48 01 00 00 00 48 48 48 48 1C 00 00 00 48 48 48 48 01 05 00 00 00 00 00 05 15 00 00 00 05 63 B4 28 0A CF B1 B7 D1 40 E9 C6 E8 03 00 00 48 48 48 48 28 00 00 00 48 48 48 48 57 00 49 00 4E 00 2D 00 50 00 35 00 44 00 49 00 46 00 51 00 42 00 30 00 43 00 31 00 47 00 5C 00 6D 00 61 00 63 00 00 00 38 00 00 00 48 48 48 48 58 02 00 00 10 0E 00 00 80 F4 03 00 FF FF FF FF 07 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 AA AA 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 FF FF FF FF FF FF FF FF 00 00 00 00 FF FF FF FF 00 00 00 00 00 00 00 00 00 00 00 00
 00 00 00 00 01 00 69 00 63 00 65 00 3A 00 00 00 69 00 2E 00 00 48 48 48 48 48 48 48 00 48 48 48 48 48 48 48 01 00 00 00 48 48 48 48 1C 00 00 00 48 48 48 48 01 05 00 00 00 00 00 05 15 00 00 00 05 63 B4 28 0A CF B1 B7 D1 40 E9 C6 E8 03 00 00 48 48 48 48 28 00 00 00 48 48 48 48 57 00 49 00 4E 00 2D 00 50 00 35 00 44 00 49 00 46 00 51 00 42 00 30 00 43 00 31 00 47 00 5C 00 6D 00 61 00 63 00 00 00
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Tasks\{9C691604-1C86-496F-9A97-388265B2C111}\DynamicInfo:  03 00 00 00 1A E5 82 A7 10 11 D2 01 1A E5 82 A7 10 11 D2 01 00 00 00 00 00 00 00 00
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Tree\bxymszh\Id: "{9C691604-1C86-496F-9A97-388265B2C111}"
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Tree\bxymszh\Index: 0x00000002
HKLM\SOFTWARE\Wow6432Node\Microsoft\Tracing\xkpgcoc_RASAPI32\EnableFileTracing: 0x00000000
HKLM\SOFTWARE\Wow6432Node\Microsoft\Tracing\xkpgcoc_RASAPI32\EnableConsoleTracing: 0x00000000
HKLM\SOFTWARE\Wow6432Node\Microsoft\Tracing\xkpgcoc_RASAPI32\FileTracingMask: 0xFFFF0000
HKLM\SOFTWARE\Wow6432Node\Microsoft\Tracing\xkpgcoc_RASAPI32\ConsoleTracingMask: 0xFFFF0000
HKLM\SOFTWARE\Wow6432Node\Microsoft\Tracing\xkpgcoc_RASAPI32\MaxFileSize: 0x00100000
HKLM\SOFTWARE\Wow6432Node\Microsoft\Tracing\xkpgcoc_RASAPI32\FileDirectory: "%windir%\tracing"
HKLM\SOFTWARE\Wow6432Node\Microsoft\Tracing\xkpgcoc_RASMANCS\EnableFileTracing: 0x00000000
HKLM\SOFTWARE\Wow6432Node\Microsoft\Tracing\xkpgcoc_RASMANCS\EnableConsoleTracing: 0x00000000
HKLM\SOFTWARE\Wow6432Node\Microsoft\Tracing\xkpgcoc_RASMANCS\FileTracingMask: 0xFFFF0000
HKLM\SOFTWARE\Wow6432Node\Microsoft\Tracing\xkpgcoc_RASMANCS\ConsoleTracingMask: 0xFFFF0000
HKLM\SOFTWARE\Wow6432Node\Microsoft\Tracing\xkpgcoc_RASMANCS\MaxFileSize: 0x00100000
HKLM\SOFTWARE\Wow6432Node\Microsoft\Tracing\xkpgcoc_RASMANCS\FileDirectory: "%windir%\tracing"
...(continue)


For sure, if it is a Ransomware it had put some file into the "Tasks" folder (C://%Nome utente%/Windows/System32) in order to be executed on computer startup.


As I expected, into this folder there was a file named "bxymszh" without a file extension. 

Note: Also this file name changes if the cryptolocker is executed more than one time restoring the VM snapshot.


The content of this file are reported below:

<?xml version="1.0" encoding="UTF-16"?>
<Task version="1.2" xmlns="http://schemas.microsoft.com/windows/2004/02/mit/task">
  <RegistrationInfo />
  <Triggers>
    <LogonTrigger id="Trigger1">
      <Enabled>true</Enabled>
      <UserId>mac</UserId>
    </LogonTrigger>
  </Triggers>
  <Settings>
    <MultipleInstancesPolicy>IgnoreNew</MultipleInstancesPolicy>
    <DisallowStartIfOnBatteries>true</DisallowStartIfOnBatteries>
    <StopIfGoingOnBatteries>false</StopIfGoingOnBatteries>
    <AllowHardTerminate>true</AllowHardTerminate>
    <StartWhenAvailable>true</StartWhenAvailable>
    <RunOnlyIfNetworkAvailable>false</RunOnlyIfNetworkAvailable>
    <IdleSettings>
      <Duration>PT10M</Duration>  
      <WaitTimeout>PT1H</WaitTimeout>
      <StopOnIdleEnd>true</StopOnIdleEnd>
      <RestartOnIdle>false</RestartOnIdle>
    </IdleSettings>
    <AllowStartOnDemand>true</AllowStartOnDemand>
    <Enabled>true</Enabled>
    <Hidden>false</Hidden>
    <RunOnlyIfIdle>false</RunOnlyIfIdle>
    <WakeToRun>false</WakeToRun>
    <ExecutionTimeLimit>PT72H</ExecutionTimeLimit>
    <Priority>7</Priority>
  </Settings>
  <Actions Context="Author">
    <Exec>
      <Command>C:\Users\%USER_NAME%\AppData\Local\Temp\xkpgcoc.exe</Command>
    </Exec>
  </Actions>
  <Principals>
    <Principal id="Author">
      <UserId>HIDDEN_BY_ME</UserId>
      <LogonType>InteractiveToken</LogonType>
      <RunLevel>LeastPrivilege</RunLevel>
    </Principal>
  </Principals>
</Task>

Below is reported the Temp folder content that includes: 2 folders and one exe file that is the process that has been executed by the evil file ("Documento Numero 00020160830.pdf.exe").


Running this ransomware more than one time, exe file's name (xkpgcoc.exe) does not changes but folders name change every time.

The content of two folders "nsmFEF9.tmp" and "nsbEDF8.tmp" is a DLL file, named "System.dll".


Analyzing both DDLs, them seams to be identical, same strings, same function names (Store, Copy, Alloc), etc, but they are located in two different folders. I suppose an development mistake into the source code.



Going to the parent directory I found other files with not classic extensions. 
This name of these file, contrary to the others DOESN'T change if the malware is executed more than one time. 
We have some good IOCs :)



Going to the parent directory I found other files with not classic extensions. 
This name of these file, contrary to the others DON'T change if the malware is executed more than one time. 
We have some good IOCs :)

In brief, this Cryptolocker use the real CTB-Locker algorithm to encrypt files that until now has been not cracked. Anyway there is a gray area about it that want to summarize in some points:
  • The end-user download a zipped file protect with password that is reported in a static webpage.
  • The Onion web page located into the dark web with a bypass of the first screen.
  • The countdown is only a fake.
  • Two equals DLL files

Every of these points improved or decreased the fraudster's economy?...If the end-user after the file download removed the email? The fraudster has failed at the first step. 

How much it's not worth the trouble?

This was a very strange campaign with a very sophisticated Cryptolocker but with some ordinary mistakes did by a not expert person.

IoCs


Into \AppData\Local\:
  • aclfepwx.cb
  • aom.t 
  • cwmlmn.p 
  • jbibns.sm
  • jsrthsll.lj
  • ljyg.wqbv
  • pnvj.t
  • rcdsn.uv
  • rgfihvmy.uqmas.wp
  • s.wp
  • wb.ibkh
  • x.am
  • yjkjaryt.b

Into \System32\Tasks
  • xkpgcoc.exe

MD5: 474e163b1da51a3da12290190e508f05
SHA1: 126e8fbd68dbf76e9e20477729555049cbe89dd8

Monday 22 August 2016

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Hackers Vs Hackers - Equation Group's Cyber Weapon Leaked




One week ago in Pastebin website, a new paste was posted, its title is "Equation Group - Cyber Weapons Auction".


This paste seems to be published by a group of hackers called Shadow Brokers. The group
claims to have attack tools and exploits which is probably attributable to hacker group known like "Equation Group", likely linked NSA.
Data, including exploits and hacking tools, were published on their Github and Tumblr, but the accounts were promptly suspended.  Data links to two distinct PGP-encrypted archives.

According to the information published by Edward Snowden, USA have the responsibility for these attacks.


In the leak, we found some link with some of the hacking tools names used in the documents leaked by Edward Snowden, like "BANANAGLEE" and "EPICBANANA".

Since 2001, the Equation Group has thousands infected victims in over 30 countries worldwide from every sectors, like: government and diplomatic institutions, telecommunications, aerospace, energy, nuclear research, oil and gas industry, military, etc.

The Intercept, on last Friday, published a new set of documents from the Edward Snowden archive. These documents confirms that the files leaked by the Shadow Brokers contain authentic NSA software and hacking tools used to secretly infect computers worldwide.

Archive Analysis

The archive has two files:
  • eqgrp-free-file.xz.gpg, Shadow Brokers group released the password for free to give evidence about the leak.
  • eqgrp-auction-file.xz.gpg, Shadow Brokers group auction off the password for this archive (they are asking for 1 Million Bitcoins in an auction to release the cyber weapons and more files belonging to the arsenal of the Equation Group).

Extracting free archive in my windows lab, immediately my AV triggered three warnings about three trojan horse.
  • egregiousblunder_3.0.0.1
  • workit.py
  • ELBA (it is a compiled version of ELBA.sh)
To avoid to have my lab compromised, I decided to switch to my linux lab and extract the archive there.

Freely distributed archive contains a small amount of information that does not directly indicate the data belonging to the Equation Group.

The exploits appear to be targeting firewalls, particularly Cisco PIX/ASA, Juniper Netscreen, Fortigate, and more.

Checking the files, is possible to identify a "extrabacon_1.1.0.1", python file, where is present a piece of code that contains if-else cascading to check Cisco appliance version.

The image below report the shellcode files for each Cisco ASA version.

ExtraBacon Exploit contains a zero-day vulnerability (CVE-2016-6366) that affect the source code of Cisco ASA software that manage Simple Network Management Protocol (SNMP).
This vulnerabilty could allow an unauthenticated remote attacker to cause a reboot the of the system (Quote:. Cisco advisory).

American Security Firm, like Cisco, Fortinet, Juniper and also an Cina Firm, like TopSec, have released patchs to fix these vulnerability.


If everything is true, we are officially in a cyber warfare!!

Thursday 21 July 2016

Monday 18 July 2016

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Pokemon GO evolves in Malware GO - Part 1






















As reported from different fonts, Pokemon Go is a virtual reality game and it is also the first game developed by Nintendo for smartphone Android and iOS.

Researchers discovered an infected Android version of the mobile game Pokemon GO. The installation file (APK) was modified to include a malicious remote access tool (RAT) called DroidJack, which would give an attacker full control over a victim’s phone.The game was first released in Australia and New Zealand on July 4th and on July 6th in the US. 

The game had not been officially released globally at the same time, many gamers wishing to access the game before it was released in their country, attempted to download a copy of the game outside of legitimate channels.


PART 1 - STATIC ANALYSIS


In the first part of this article I want to do a deep dive analysis of the evil APK and compare the differences between the real and the infected App.

Who created the evil App retrieved a game's copy, inserted inside a RAT tool and spread the APK in different third part market. The attacker took advantages of frenzy of the rest of the world to play the game before to be official released in the countries.


HERE WE GOOOOOOO!!!!


First of all I think it is important to analyze the differences between PERMISSIONs included within the Manifest file.

























In the red square is highlighted a part of permissions added into the evil APK.

The user, accepting these permissions give to the attacker the full access of his SMS, contacts list, camera, microphone, Internal and external (SD card) memory, etc.

Another evidence is reported in the image below. In the green square is present the safe part of the APK, in the red square is reported the padding code, where different droidjack server services are invoked to be enabled.
In the same part is possible to read the declaration of two activities, CamSnapDJ and VideoSnapDJ
Two receivers are also declared:
  • Connector to run on boot completed
  • CallListener to read phone state
























Inspecting content of both APK files, stand out that three different packages were added by the attacker. 


Droidjack is also known as SandroRat, below is reported the evidence:


The attacker used Java Crypto library to encrypt communications with AES (Advanced Encryption Standard) algorithm.

Source: https://docs.oracle.com/javase/7/docs/api/javax/crypto/Cipher.html

I was able to decode the Key from the byte array


Below is reported the URL contacted and the port used to communicate with the C&Cs.



This malware identifies the device and creates a Database to store these information. Then everything is sent to the website http://droidjack(dot)net/storeReport(dot)php.
































In the class bs the attacker verifies if the device is rooted by checking into the fonder /system/app/ the existence of the APK file Superuser.apk.

If the smartphone is rooted, this malware will have device full control.



The image below reports how this malware monitors and stores information about SMS incoming, outgoing, and in drafted.



In the last picture I reported how the Whatsapp database is read and stolen.




Finally, this report evidences how third part market that give you the opportunity to download APK for free, could spread malicious App. To protect yourself from possible infections, download apps from official app store and not from third-party site.


There's no such thing as a free lunch!!


IOC:

SHA256: 15db22fd7d961f4d4bd96052024d353b3ff4bd135835d2644d94d74c925af3c4
MD5: d350cc8222792097317608ea95b283a8
Domain: 
  • http://pokemon.no-ip.org (IP address: 88.223.178.130)
  • http://droidjack.net/storeReport.php (IP: 162.251.80.24)


Dynamic analysis is coming soon...