Modified by: Rika Joi Gregorio
ALIASES:

Worm:Win32/Chiviper.C (Microsoft); Trojan.Gen (Symantec); Trojan.Win32.Generic!BT (Sunbelt)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • 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

File Size: 28,160 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 21 Nov 2012

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.

Other System Modifications

This worm adds the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\SessionManager
PendingFileRenameOperations = %System%\ws2helop.dll.{random}.tmp

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet\
Control\Session Manager
ExcludeFromKnownDlls = "usp10.dll"

(Note: The default value data of the said registry entry is {random values}.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "2"

(Note: The default value data of the said registry entry is 1.)

Dropping Routine

This worm drops the following files:

  • %Windows%\usp10.dll
  • %System%\ws2helpxp.dll

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.. %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.)

Download Routine

This worm downloads an updated copy of itself from the following website(s):

  • bbz.{BLOCKED}w.com/110/jc928xx.txt

It saves the files it downloads using the following names:

  • %Temporary Internet Files%\Content.IE5\{random}\jc928xx.txt

Other Details

This worm connects to the following possibly malicious URL:

  • http://tj1012.{BLOCKED}y.com/tj1012/post.asp?d10=08-00-27-DA-9F-73&dll=ver-tongji-116&d21=56&d22=xp

It deletes itself after execution.

NOTES:

This worm drops copies of itself in all folders on fixed drives and removable drives containing .EXE files. This allows the worm to be loaded when an .EXE file attempts to load the legitimate USP10.DLL.

This happens when an .EXE file loads DLL components from the same folder before checking in the system folders for the component DLL.

This worm also overwrites %System%\ws2help.dll.