WORM_NEERIS.JWE
VirTool:Win32/Injector.gen!B (Microsoft); BackDoor-DOQ.gen.e (McAfee); Packed.Generic.267 (Symantec); Trojan.Generic.2367796 (FSecure)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This worm arrives by connecting affected removable drives to a system. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
It deletes the initially executed copy of itself.
TECHNICAL DETAILS
Arrival Details
This worm arrives by connecting affected removable drives to a system.
It 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%\dllcache.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)
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
netmon = "%System%\dllcache.exe"
Other System Modifications
This worm adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%Windows%\system\dllcache.exe = "%Windows%\system\dllcache.exe:*:Microsoft Enabled"
Propagation
This worm drops the following copy(ies) of itself in all removable drives:
- strongkey-rc1.3-build-208.exe
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
The said .INF file contains the following strings:
[autorun]
shellexecute=strongkey-rc1.3-build-208.exe
action=Open folder to view files
shell\default=Open
shell\default\command=strongkey-rc1.3-build-208.exe
shell=default
Dropping Routine
This worm drops the following files:
- %System%\drivers\sysdrv32.sys
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)
Other Details
This worm deletes the initially executed copy of itself