BKDR_GAMARUE.NC
Worm:Win32/Gamarue.F (Microsoft), Troj/Agent-XGN (Sophos), a variant of Win32/Kryptik.AJEH trojan (Eset)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
Spammed via email
This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.
It does not have any propagation routine.
It listens on ports. However, as of this writing, the said sites are inaccessible.
It does not have any downloading capability.
It does not have any information-stealing capability.
TECHNICAL DETAILS
UDP port 8000 (iRDMI)
37,376 bytes
EXE
Yes
31 Jul 2012
Modifies system registry
Arrival Details
This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.
Installation
This Trojan drops the following copies of itself into the affected system:
- {All User's Profile}\Local Settings\Temp\ms{random characters}.{extension name}
- %System Root%\Documents and Settings\All Users\svchost.exe
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
Autostart Technique
This Trojan 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 User's Profile}\Local Settings\Temp\ms{random characters}.{extension name}"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
SunJavaUpdateSched = "%System Root%\Documents and Settings\All Users\svchost.exe"
Other System Modifications
This Trojan creates the following registry entry(ies) to bypass Windows Firewall:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
{malware path and filename} = "{malware path and filename}:*:Enabled:AutomaticCradlePro"
Propagation
This Trojan does not have any propagation routine.
Backdoor Routine
This Trojan listens on the following ports:
- 8000
It connects to the following URL(s) to send and receive commands from a remote malicious user:
- {BLOCKED}ep.ru
However, as of this writing, the said sites are inaccessible.
Download Routine
This Trojan does not have any downloading capability.
Information Theft
This Trojan does not have any information-stealing capability.
NOTES:
The extension name used in one of this backdoor's dropped copy may be any of the following:
- BAT
- CMD
- COM
- EXE
- PIF
- SCR
It does not have rootkit capabilities.
It does not exploit any vulnerability.
SOLUTION
9.200
9.306.01
05 Aug 2012
9.307.00
06 Aug 2012
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
Restart in Safe Mode
Step 3
Identify and terminate files detected as BKDR_GAMARUE.NC
- If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
Step 4
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 User's Profile}\Local Settings\Temp\ms{random characters}.{extension name}"
- {random number} = "{All User's Profile}\Local Settings\Temp\ms{random characters}.{extension name}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- SunJavaUpdateSched = "%System Root%\Documents and Settings\All Users\svchost.exe"
- SunJavaUpdateSched = "%System Root%\Documents and Settings\All Users\svchost.exe"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
- {malware path and filename} = "{malware path and filename}:*:Enabled:AutomaticCradlePro"
- {malware path and filename} = "{malware path and filename}:*:Enabled:AutomaticCradlePro"
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_GAMARUE.NC. 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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