Encyclopedia entry
Updated: Nov 10, 2010 | Published: Dec 30, 2008

TA08-297A (other)
CVE-2008-4250 (other)
VU827267 (other)
Win32/Conficker.A (CA)
Mal/Conficker-A (Sophos)
Trojan.Win32.Agent.bccs (Kaspersky)
W32.Downadup.B (Symantec)
Confickr (other)

Worm:Win32/Conficker.B is a worm that infects other computers across a network by exploiting a vulnerability in the Windows Server service (SVCHOST.EXE). If the vulnerability is successfully exploited, it could allow remote code execution when file sharing is enabled. It may also spread via removable drives and weak administrator passwords. It disables several important system services and security products.

Microsoft also recommends that users ensure that their network passwords are strong to prevent this worm from spreading via weak administrator passwords. More information is available here.

Microsoft also recommends that users apply an update that changes the AutoPlay functionality in Windows to prevent this worm from spreading via USB drives. More information is available in the Microsoft Knowledgebase Article KB971029.

The following system changes may indicate the presence of this malware:
The following services are disabled or fail to run:
Windows Update Service
Background Intelligent Transfer Service
Windows Defender
Windows Error Reporting Services

Some accounts may be locked out due to the following registry modification, which may flood the network with connections:
"TcpNumConnections" = "0x00FFFFFE"

Users may not be able to connect to websites or online services that contain the following strings:
virus, spyware, malware, rootkit, defender, microsoft, symantec, norton, mcafee, trendmicro, sophos, panda, etrust, networkassociates, computerassociates, f-secure, kaspersky, jotti, f-prot, nod32, eset, grisoft, drweb, centralcommand, ahnlab, esafe, avast, avira, quickheal, comodo, clamav, ewido, fortinet, gdata, hacksoft, hauri, ikarus, k7computing, norman, pctools, prevx, rising, securecomputing, sunbelt, emsisoft, arcabit, cpsecure, spamhaus, castlecops, threatexpert, wilderssecurity, windowsupdate.

and more here.