Trojan.Win32.Generic!BT (Sunbelt)


Windows 2000, Windows XP, Windows Server 2003


  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes


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.


File Size: 28,008 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 14 May 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.


This worm drops the following copies of itself into the affected system:

  • %Windows%\sysmonxp.exe

(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:

SysMonXP = "%Windows%\SysMonXP.exe"

Other System Modifications

This worm deletes the following registry keys:




Dropping Routine

This worm drops the following files:

  • %Windows%\firewalllogger.txt
  • %Windows%\zippedbase64.tmp

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

This report is generated via an automated analysis system.


Minimum Scan Engine: 9.200

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

[ Learn More ]

Step 3

Delete this registry value

[ Learn More ]

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
    • SysMonXP = "%Windows%\SysMonXP.exe"

Step 4

Search and delete these components

[ Learn More ]
There may be some components that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %Windows%\firewalllogger.txt
  • %Windows%\zippedbase64.tmp

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_NETSKY.Q. 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 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.

  • In HKEY_CLASSES_ROOT\CLSID\{E6FB5E20-DE35-11CF-9C87-00AA005127ED}
    • InProcServer32
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer
    • PINF
  • In HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services
    • WksPatch

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