RANSOM_SERBRAN.A
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted: No
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. It may be dropped by other malware.
TECHNICAL DETAILS
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.
It may be dropped by the following malware:
- Ransom_SERBRAN.BLD
Dropping Routine
This Trojan drops the following files:
- {Encrypted File path}\{Original Filename and Extension of Encrypted File}INSTRUCTION.html -> Ransom Note
- %User Temp%\sys.vbs -> Contains registry commands, as part of malware’s routine
- %User Temp%\TRENUTNO OBRADJIVANJE.txt -> Log File, contains the list of encrypted files
(Note: %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 Details
This Trojan renames encrypted files using the following names:
- {Original Filename and Extension}.velikasrbija
It does the following:
- Encrypting all file types
- Bypass UAC (User Account Control)
- Uses Anti-Sandbox Techniques
- Remove System Restore Points
NOTES:
The ransomware drops/displays the following ransom note:
SOLUTION
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 this file
- {Encrypted File path}\{Original Filename and Extension of Encrypted File}INSTRUCTION.html
- %User Temp%\sys.vbs
- %User Temp%\TRENUTNO OBRADJIVANJE.txt
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_SERBRAN.A. 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
Restore encrypted files from backup.
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