WORM_IRCBOT.ANA
VirTool:Win32/Injector.gen!CA (Microsoft); W32/YahLover.worm (McAfee); W32.IRCBot (Symantec); Trojan.Win32.Jorik.IRCbot.io (Kaspersky); Backdoor.Win32.IRCBot (Sunbelt); Trojan horse SHeur3.BCVP (AVG)
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm 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
58,880 bytes
EXE
Yes
09 Apr 2013
Arrival Details
This worm 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 worm drops the following copies of itself into the affected system:
- %Windows%\nvsvc32.exh
(Note: %Windows% is the Windows folder, which is usually C:\Windows.)
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
NVIDIA driver monitor = "%Windows%\nvsvc32.exe"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
NVIDIA driver monitor = "%Windows%\nvsvc32.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Terminal Server\
Install\Software\Microsoft\
Windows\CurrentVersion\Run
NVIDIA driver monitor = "%Windows%\nvsvc32.exe"
Other System Modifications
This worm deletes the following files:
- %System Root%\mdlu.dl
- %System Root%\mtdlh.dl
- %Windows%\nvsvc32.exh
- %Windows%\mdlu.dl
- %Windows%\mtdlh.dl
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %Windows% is the Windows folder, which is usually C:\Windows.)
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
{malware path and file name} = "{malware path and file name}:*:enabled:nvidia driver monitor"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
{malware path and file name} = "%Windows%\nvsvc32.exe:*:Enabled:NVIDIA driver monitor"
Dropping Routine
This worm drops the following files:
- %Windows%\nvsvc32.exe
(Note: %Windows% is the Windows folder, which is usually C:\Windows.)
Other Details
This worm connects to the following possibly malicious URL:
- http://{BLOCKED}5.106.162/index.php
This report is generated via an automated analysis system.
SOLUTION
9.300
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\Run
- NVIDIA driver monitor = "%Windows%\nvsvc32.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- NVIDIA driver monitor = "%Windows%\nvsvc32.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Terminal Server\Install\Software\Microsoft\Windows\CurrentVersion\Run
- NVIDIA driver monitor = "%Windows%\nvsvc32.exe"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
- {malware path and file name} = "{malware path and file name}:*:enabled:nvidia driver monitor"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
- {malware path and file name} = "%Windows%\nvsvc32.exe:*:Enabled:NVIDIA driver monitor"
Step 4
Search and delete this file
- %Windows%\nvsvc32.exe
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_IRCBOT.ANA. 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 this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- %System Root%\mdlu.dl
- %System Root%\mtdlh.dl
- %Windows%\nvsvc32.exh
- %Windows%\mdlu.dl
- %Windows%\mtdlh.dl
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