TROJ_CRIBIT.O
Ransom:Win32/Tescrypt.A (Microsoft); Ransom-FYG!209A288C6820 (McAfee); Trojan.Gen.2 (Symantec); Trojan-Ransom.Win32.Bitman.d (Kaspersky); Troj/EccKrypt-A (Sophos); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse SHeur4.CGOQ (AVG)
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
TECHNICAL DETAILS
290,816 bytes
EXE
Yes
27 Mar 2015
Arrival Details
This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Installation
This Trojan drops the following copies of itself into the affected system:
- %User Profile%\Application Data\gtaepsg.exe
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
crypto13 = "%User Profile%\Application Data\gtaepsg.exe"
Other System Modifications
This Trojan modifies the following registry entries:
HKEY_CURRENT_USER\Control Panel\Desktop
WallpaperStyle = "0"
(Note: The default value data of the said registry entry is 2.)
HKEY_CURRENT_USER\Control Panel\Desktop
TileWallpaper = "0"
(Note: The default value data of the said registry entry is 0.)
Dropping Routine
This Trojan drops the following files:
- %User Profile%\Application Data\key.dat
- %User Profile%\Application Data\log.html
- %Desktop%\HELP_TO_DECRYPT_YOUR_FILES.bmp
- %Desktop%\CryptoLocker.lnk
- %Desktop%\HELP_TO_DECRYPT_YOUR_FILES.txt
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
Other Details
This Trojan connects to the following possibly malicious URL:
- http://7tno4hib47vlep5o.{BLOCKED}b.org/state.php?{random characters}
- http://7tno4hib47vlep5o.{BLOCKED}b.blutmagie.de/state.php?{random characters}
- http://7tno4hib47vlep5o.{BLOCKED}b.fi/state.php?{random characters}
- {BLOCKED}.70.4
- {BLOCKED}1.226.206
- {BLOCKED}.26.27
This report is generated via an automated analysis system.
SOLUTION
9.750
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.
Step 2
Restart in Safe Mode
Step 3
Delete this registry value
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- crypto13 = "%User Profile%\Application Data\gtaepsg.exe"
Step 4
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_CURRENT_USER\Control Panel\Desktop
- From: WallpaperStyle = "0"
To: WallpaperStyle = ""2""
- From: WallpaperStyle = "0"
- In HKEY_CURRENT_USER\Control Panel\Desktop
- From: TileWallpaper = "0"
To: TileWallpaper = ""0""
- From: TileWallpaper = "0"
Step 5
Search and delete these components
- %User Profile%\Application Data\key.dat
- %User Profile%\Application Data\log.html
- %Desktop%\HELP_TO_DECRYPT_YOUR_FILES.bmp
- %Desktop%\CryptoLocker.lnk
- %Desktop%\HELP_TO_DECRYPT_YOUR_FILES.txt
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_CRIBIT.O. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.
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