Ransom:Win32/Cerber(Microsoft);Troj.Ransom.W32.Zerber!c(AegisLab)
Windows
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.
It connects to certain websites to send and receive information. It terminates itself if it detects it is being run in a virtual environment. It deletes the initially executed copy of itself.
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 files:
(Note: %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.. %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on 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 System Modifications
This Trojan adds the following registry entries as part of its installation routine:
HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = %User Temp%\{random filename}.bmp
Process Termination
This Trojan terminates the following processes if found running in the affected system's memory:
Other Details
This Trojan connects to the following website to send and receive information:
It encrypts files with the following extensions:
It renames encrypted files using the following names:
It terminates itself if it detects it is being run in a virtual environment.
It does the following:
It deletes the initially executed copy of itself
NOTES:
The malware changes the affected system wallpaper to the following image:
The _HELP_HELP_HELP_{random}.hta contains the following information:
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
Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.
Step 3
Restart in Safe Mode
Step 4
Search and delete these files
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_CERBER.F117AK. 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.
Step 6
Reset your Desktop properties
Step 7
Restore encrypted files from backup.