W32.HLLW.Deloder

While Symantec Security Response is seeing an increase in submissions of W32.HLLW.Deloder, Symantec DeepSight Threat Management System has shown an overall decrease in activity on port 445. Security Response will continue to monitor this threat, and take action as appropriate.

W32.HLLW.Deloder is a network-aware worm that attempts to connect to a target host, using TCP port 445. This worm affects Windows 2000 and Windows XP only.

If the worm makes a successful connection, it copies the file, Inst.exe, to locations that are hard-coded in the worm. Inst.exe is a backdoor Trojan component that is detected as Backdoor.Dvldr. Then, W32.HLLW.Deloder will load from the Startup folder when you start Windows.

W32.HLLW.Deloder attempts to launch several remote services, which:

• Copies and executes the backdoor Trojan
• Copies and executes the worm
• Deletes the default shares
• Changes the attributes of the worm and backdoor Trojan to Read only

The worm exists as the Dvldr32.exe file and is packed with ASPack.

Protection

• Initial Rapid Release version March 9, 2003
• Latest Rapid Release version July 19, 2008 revision 019
• Initial Daily Certified version March 9, 2003
• Latest Daily Certified version January 20, 2009 revision 048
• Initial Weekly Certified release date March 9, 2003

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Threat Assessment

Wild

• Wild Level: Medium
• Number of Infections: 50 - 999
• Number of Sites: More than 10
• Geographical Distribution: Medium
• Threat Containment: Easy
• Removal: Moderate

Damage

• Damage Level: Medium

Distribution

• Distribution Level: Medium