BKDR_ANDROM.HF
Worm:Win32/Gamarue.F (Microsoft), W32/Gamarue-BK (SOPHOS)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Backdoor
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It deletes the initially executed copy of itself.
TECHNICAL DETAILS
108,625 bytes
EXE
Yes
31 Aug 2013
Arrival Details
This backdoor 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 backdoor drops the following copies of itself into the affected system and executes them:
- %All Users Profile%\Local Settings\Temp\cc{random characters}.{varying extension name}
(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.)
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
{random number} = "%All Users Profile%\Local Settings\Temp\cc{random characters}.{varying extension name}"
Other Details
This backdoor connects to the following possibly malicious URL:
- http://{BLOCKED}d.ru/static.php
- http://{BLOCKED}iuojy.ru/2ldr.php
- http://{BLOCKED}iuojy.ru/3ldr.php
- http://{BLOCKED}iuojy.ru/41ldr.php
- http://{BLOCKED}iuojy.ru/51ldr.php
- http://{BLOCKED}iuojy.ru/6ldr.php
It deletes the initially executed copy of itself
NOTES:
The {varying extension name} contained in the malware's file name can be any of the following:
- exe
- com
- scr
- pif
- cmd
- bat
SOLUTION
9.300
10.254.02
02 Sep 2013
10.255.00
03 Sep 2013
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\Run
- {random number} = "%All Users Profile%\Local Settings\Temp\cc{random characters}.{varying extension name}"
- {random number} = "%All Users Profile%\Local Settings\Temp\cc{random characters}.{varying extension name}"
Step 4
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_ANDROM.HF. 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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