WORM_RBOT.YV
Backdoor:Win32/Rbot (Microsoft); W32/Sdbot.worm.gen.y (McAfee); W32.Spybot.Worm (Symantec); Backdoor.Win32.Rbot.wi (Kaspersky); Trojan.Win32.Ircbot!cobra (v) (Sunbelt); Trojan horse IRC/BackDoor.SdBot.56.BI (AVG)
Windows 2000, Windows XP, Windows Server 2003
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.
It deletes itself after execution.
TECHNICAL DETAILS
143,360 bytes
EXE
Yes
04 Jun 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:
- %System%\winu32.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
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
update service = "winu32.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunServices
update service = "winu32.exe"
Other System Modifications
This worm deletes the following files:
- %User Temp%\Xý_CHAR(0x12)_
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
It adds the following registry keys:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\RunServices
HKEY_CURRENT_USER\Software\Microsoft\
OLE
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
OLE
update service = "winu32.exe"
Other Details
This worm deletes itself after execution.
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 key
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
- RunServices
- In HKEY_CURRENT_USER\Software\Microsoft
- OLE
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
- update service = "winu32.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
- update service = "winu32.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\OLE
- update service = "winu32.exe"
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_RBOT.YV. 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.
- %User Temp%\Xý_CHAR(0x12)_
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