Modified by: Rhena Inocencio


Worm:Win32/Conficker.D (Microsoft), W32/Conficker.worm.gen.d (McAfee)


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: Varies
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 19 Mar 2009

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:

  • %System%\{Random file name}.dll

(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.)

It injects itself into the following processes running in the affected system's memory:

  • services.exe
  • svchost.exe -k NetworkService

Autostart Technique

This worm registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:

Services\{Service Name}
ImagePath = "%SystemRoot%\system32\svchost.exe -k netsvcs"

Services\{Service Name}\Parameters
ServiceDll = "{Malware path and file name}"

Other Details

This worm connects to the following possibly malicious URL:

  • http://{psuedorandom domain}

It connects to the following time servers to determine the current date:



This worm attempts to propagate through the internet via the Server Service Vulnerability using external IP addresses.

It concatenates 2 strings from the following list to use as the {Service name}:

  • access
  • agent
  • App
  • Audio
  • auto
  • DM
  • ER
  • Event
  • help
  • Ias
  • Ir
  • Lanman
  • logon
  • man
  • mgmt
  • mon
  • Net
  • Ntms
  • prov
  • Ras
  • Remote
  • Sec
  • serv
  • Server
  • Service
  • Srv
  • srv
  • SR
  • Svc
  • svc
  • Tapi
  • Trk
  • W32
  • win
  • Wmdm
  • Wmi
  • wsc
  • wuau
  • xml

It may also drop a copy of itself in the following folders:

  • %Program Files%\Internet Explorer
  • %Program Files%\Movie Maker
  • %Program Files%\Windows Media Player
  • %Program Files%\Windows NT


Minimum Scan Engine: 9.300
VSAPI OPR PATTERN File: 5.909.00
VSAPI OPR PATTERN Date: 20 Mar 2009

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 WORM_DOWNAD.KK

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

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\SYSTEM\CurrentControlSet\Services\{Service Name}
    • ImagePath = "%SystemRoot%\system32\svchost.exe -k netsvcs"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\{Service Name}\Parameters
    • ServiceDll = "{Malware path and file name}"

Step 5

Search and delete the file detected as WORM_DOWNAD.KK

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files in the search result.

Step 6

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

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