WORM_AUTORUN.GYT
Worm:Win32/Cridex.B (Microsoft), W32.SillyDC (Symantec), , PWS-Zbot.gen.ni (McAfee), Worm.Win32.AutoRun.czje (Kaspersky)
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 adds registry entries to enable its automatic execution at every system startup.
It deletes registry entries, causing some applications and programs to not function properly.
It deletes the initially executed copy of itself.
TECHNICAL DETAILS
58,368 bytes
EXE
Yes
21 Nov 2011
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:
- %User Profile%\Application Data\KB00445963.EXE
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)
It terminates the execution of the copy it initially executed and executes the copy it drops instead.
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
KB00445963.exe = "%User Profile%\Application Data\KB00445963.EXE"
Other System Modifications
This worm adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
GlobalUserOffline = "0"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
ProxyEnable = "0"
It deletes the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
AutoConfigURL = "{user defined}"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
ProxyOverride = "{user defined}"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
ProxyServer = "{user defined}"
Other Details
This worm connects to the following possibly malicious URL:
- http://{BLOCKED}zerberze.ru/724/in/
It deletes the initially executed copy of itself
SOLUTION
9.200
8.591.00
22 Nov 2011
Step 1
Prior to scanning your system, Windows XP, Windows Server 2003, Windows Vista, and Windows 7 users should make sure you disable System Restore to be able to conduct a full scan.
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
- GlobalUserOffline = "0"
- GlobalUserOffline = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
- ProxyEnable = "0"
- ProxyEnable = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- KB00445963.exe = "%User Profile%\Application Data\KB00445963.EXE"
- KB00445963.exe = "%User Profile%\Application Data\KB00445963.EXE"
Step 4
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_AUTORUN.GYT 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 5
Restore these deleted registry keys/values from backup
*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
AutoConfigURL = "{user defined}"
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
ProxyOverride = "{user defined}"
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
ProxyServer = "{user defined}"
Did this description help? Tell us how we did.