BKDR_ANDROM.AT
Worm:Win32/Gamarue (Microsoft), Backdoor.Trojan (Symantec), PWS-Zbot.gen.aob (McAfee)
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.
TECHNICAL DETAILS
66919 bytes
EXE
Yes
16 Oct 2012
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:
- {All User's Profile}\Local Settings\Temp\ms{random characters}.{extension name}
- {All User's Profile}\svchost.exe
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\Run
SunJavaUpdateSched = "{All User's Profile}\svchost.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
{random number} = "{All User's Profile}\Local Settings\Temp\ms{random characters}.{extension name}"
Other System Modifications
This backdoor 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 file name} = "{malware path and file name} "{malware path and file name}:*:Enabled:{malware file name without extension}""
Other Details
This backdoor connects to the following possibly malicious URL:
- http://{BLOCKED}.{BLOCKED}.68.244/image.php
- http://{BLOCKED}.{BLOCKED}.114.163/r.pack
NOTES:
The {extension name} is any of the following:
- BAT
- CMD
- COM
- EXE
- PIF
- SCR
SOLUTION
9.200
9.468.04
16 Oct 2012
9.469.00
17 Oct 2012
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
Scan your computer with your Trend Micro product and note files detected as BKDR_ANDROM.AT
Step 3
Restart in Safe Mode
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\Run
- SunJavaUpdateSched = "{All User's Profile}\svchost.exe"
- SunJavaUpdateSched = "{All User's Profile}\svchost.exe"
- 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\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
- {malware path and file name} = "{malware path and file name} "{malware path and file name}:*:Enabled:{malware file name without extension}""
- {malware path and file name} = "{malware path and file name} "{malware path and file name}:*:Enabled:{malware file name without extension}""
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_ANDROM.AT. 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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