Analysis by: Jasen Sumalapao


Backdoor:Win32/Poison.E (Microsoft), Trojan.Win32.Agent.tkql (Kaspersky), Generic PWS.y!1ij (NAI), Troj/Agent-XNE (Sophos), Trojan.Win32.Generic!BT (Sunbelt), TR/Spy.16896.281 (Antivir), Gen:Trojan.Heur.FU.bqW@a4uT4@bb (Bitdefender), W32/Agent.TKQL!tr (Fortinet), Virus.Worm.Koobface (Ikarus), Win32/Poison.NHM trojan (NOD32), Trj/StartPage.DAW (Panda), Trojan-PSW.Win32.Nilage (VBA32)


Windows 2000, Windows XP, Windows Server 2003


  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes


Infection Channel: Dropped by other malware, Downloaded from the Internet

This is a Trend Micro detection for a backdoor component exploiting a Java Runtime Environments (JRE) vulnerability.

This backdoor may be downloaded by other malware/grayware from remote sites.

It connects to certain websites to send and receive information. It executes certain actions WITHIN the affected computer. It deletes itself after execution.


File Size: 16,896 bytes
File Type: EXE, DLL
Memory Resident: Yes
Initial Samples Received Date: 27 Aug 2012
Payload: Connects to URLs/IPs

Arrival Details

This backdoor may be downloaded by the following malware/grayware from remote sites:


It may be downloaded from the following remote sites:

  • http://{BLOCKED}.{BLOCKED}.104.149/public/meeting/Flash_update.exe
  • http://ok.{BLOCKED}


This backdoor drops the following component file(s):

  • %System%\mspmsnsv.dll - also detected as BKDR_POISON.BLW

(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.)

Its DLL component is injected to the following process(es):

  • svchost.exe

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • 808834455

Autostart Technique

This backdoor adds the following registry entries to enable its automatic execution at every system startup:

Control\Session Manager
PendingFileRenameOperations = "%User Temp%\{random file name}.dat"

Other Details

This backdoor connects to the following website to send and receive information:

  • hello.{BLOCKED}

It executes the following:

  • Open and List active ports
  • Manage registry, processes, services, devices, and installed applications
  • Perform remote shell
  • Downloads and execute other malicious files
  • Update, restart, terminate itself
  • Capture screen shots, webcam, audio
  • Log keystrokes and active window
  • Perform a shell command

It deletes itself after execution.


Minimum Scan Engine: 9.200
VSAPI OPR PATTERN File: 9.353.00
VSAPI OPR PATTERN Date: 28 Aug 2012

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Scan your computer with your Trend Micro product and note files detected as BKDR_POISON.BLW

Step 3

Remove malware/grayware files that dropped/downloaded BKDR_POISON.BLW

Step 4

Restart in Safe Mode

[ Learn More ]

Step 5

Delete the registry entry with an unknown data 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\SYSTEM\CurrentControlSet\Control\Session Manager
    • PendingFileRenameOperations = "%User Temp%\{random file name}.dat"

Step 6

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

Did this description help? Tell us how we did.