Content

W32/Conficker.worm

Type
Virus
SubType
Win32
Discovery Date
11/24/2008
Length
varies
Minimum DAT
5444 (11/24/2008)
Updated DAT
6539 (11/23/2011)
Minimum Engine
5.4.00
Description Added
11/24/2008
Description Modified
11/22/2011 10:22 AM (PT)
Risk Assessment
Corporate User
Low-Profiled
Home User
Low-Profiled

Tab Navigation

Characteristics

-----Updated on Nov 22 , 2011-----------

Aliases -

  • Kaspersky - Net-Worm.Win32.Kido.ih
  • NOD32 - a variant of Win32/Conficker.X
  • Ikarus - Net-Worm.Win32.Kido
  • Microsoft - Worm:Win32/Conficker.B

The following file has been added to the system.

  • [Removable Drive:]\RECYCLER\S-5-[varies]\jwgkvsq.vmx

The malware also drops an autorun.inf file into the root of all removable drives and mapped drives in an attempt to autorun an executable when the drive is accessed.

The file "AutoRun.inf" is pointing to the malware binary executable. When the removable or networked drive is accessed from a machine supporting the Autorun feature, the malware is launched automatically.

The following registry keys have been added to the system.

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\fuuomyu
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\safqdqya

The following registry value has been added to the system.

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List\
    4317 = TCP = "4317:TCP:*:Enabled:sdzcw"

The following registry values have been modified .

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RSVP\Parameters\StartBlocker = "Global\_RAPI_EVENT_NAME-C3E99E67-3B98-4E7E-91DAB5734F70E6ED"
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RSVP\Parameters\StartBlocker = ""
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RSVP\Parameters\Requests = "RAPIRpc Main-E17294EF-D5EC-40C0-B14DC2CDD7129511"
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RSVP\Parameters\Requests = ""
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RSVP\Parameters\Upcalls = "RAPIRpc Thread-6C1FCF96-AA8F-4B79-8A11E01958C1A170"
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RSVP\Parameters\Upcalls = ""

---------------------

----Update on March 10, 2009---

The risk assessment of this threat has been updated to Low-Profiled due to media attention at

http://www.thetechherald.com/article.php/200911/3157/Conficker-Worm-fighting-back-a-new-variant-discovered-disables-security-measures

A new variant of W32/Conficker.worm has been seen spreading.  It copies itself to the following pathes:

  • %Sysdir%\[Random].dll
  • %Program Files%\Internet Explorer\[Random].dll
  • %Program Files%\Movie Maker\[Random].dll
  • %Program Files%\Windows Media Player\[Random].dll
  • %Program Files%\Windows NT\[Random].dll

It disables the following services:

  • WerSvc
  • ERSvc
  • BITS
  • wuauserv
  • WinDefend
  • wscsvc

It hooks the following functions in dnsapi.dll :

  • Query_Main
  • DnsQuery_W
  • DnsQuery_UTF8
  • DnsQuery_A

It hooks the following functions in ws2_32.dll:

  • sendto

The worm deletes the following registry key to disable restarting in safe mode:

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SafeBoot

It deletes the following registry keys:

  • HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\ShellServiceObjects\{FD6905CE-952F-41F1-9A6F-135D9C6622CC}
  • HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run\Windows Defender

It terminates the processes that contains the following strings in name:

  • wireshark
  • unlocker
  • tcpview
  • sysclean
  • scct_
  • regmon
  • procmon
  • procexp
  • ms08-06
  • mrtstub
  • mrt.
  • mbsa.
  • klwk
  • kido
  • kb958
  • kb890
  • hotfix
  • gmer
  • filemon
  • downad
  • confick
  • avenger
  • autoruns

In order to block users access to security-related domains, prevents network access to any domains that contain the following strings:

  • windowsupdate
  • wilderssecurity
  • virus
  • virscan
  • trojan
  • trendmicro
  • threatexpert
  • threat
  • technet
  • symantec
  • sunbelt
  • spyware
  • spamhaus
  • sophos
  • secureworks
  • securecomputing
  • safety.live
  • rootkit
  • rising
  • removal
  • quickheal
  • ptsecurity
  • prevx
  • pctools
  • panda
  • onecare
  • norton
  • norman
  • nod32
  • networkassociates
  • mtc.sri
  • msmvps
  • msftncsi
  • mirage
  • microsoft
  • mcafee
  • malware
  • kaspersky
  • k7computing
  • jotti
  • ikarus
  • hauri
  • hacksoft
  • hackerwatch
  • grisoft
  • gdata
  • freeav
  • free-av
  • fortinet
  • f-secure
  • f-prot
  • ewido
  • etrust
  • eset
  • esafe
  • emsisoft
  • dslreports
  • drweb
  • defender
  • cyber-ta
  • cpsecure
  • conficker
  • computerassociates
  • comodo
  • clamav
  • centralcommand
  • ccollomb
  • castlecops
  • bothunter
  • avira
  • avgate
  • avast
  • arcabit
  • antivir
  • anti-
  • ahnlab
  • agnitum

The latest Conficker is known to generate 50,000 domain names using its own generator algorithm. The following is its disassembly snapshot.

The following suffixes are appended to any generated domains. It uses 116 different suffixes for example:

  • com.ve
  • com.uy
  • com.ua
  • com.tw
  • com.tt
  • com.tr
  • com.sv
  • com.py
  • com.pt
  • com.pr
  • com.pe
  • com.pa
  • com.ni
  • com.ng
  • com.mx
  • com.mt
  • com.lc
  • com.ki
  • com.jm
  • com.hn
  • com.gt
  • com.gl
  • com.gh
  • com.fj
  • com.do
  • com.co
  • com.bs
  • com.br
  • com.bo
  • com.ar
  • com.ai
  • com.ag
  • co.za
  • co.vi
  • co.uk
  • co.ug
  • co.nz
  • co.kr
  • co.ke
  • co.il
  • co.id
  • co.cr

-------------------------------------------------------------

When executed, the worm copies itself using a random name to the %Sysdir% folder.

(Where %Sysdir% is the Windows system folder; e.g. C:\Windows\System32)

It modifies the following registry key to create a randomly-named service on the affected syetem:

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\{random}\Parameters\"ServiceDll" = "Path to worm"
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\{random}\"ImagePath" = %SystemRoot%\system32\svchost.exe -k netsvcs

Attempts connections to one or more of the following websites to obtain the public ip address of the affected computer.

  • hxxp://www.getmyip.org
  • hxxp://getmyip.co.uk
  • hxxp://checkip.dyndns.org
  • hxxp://whatsmyipaddress.com

Attempts to download a malware file from the remote website: (Rogue Russian site is up but not serving file anymore)

  • hxxp://trafficconverter.biz/[Removed]antispyware/[Removed].exe

Starts a HTTP server on a random port on the infected machine to host a copy of the worm.

Continuously scans the subnet of the infected host for vulnerable machines and executes the exploit. If the exploit is successful, the remote computer will then connect back to the http server and download a copy of the worm.

Later variants of w32/Conficker.worm are using scheduled tasks and Autorun.inf file to replicate on to non vulnerable systems or to reinfect previously infected systems after they have been cleaned.

Symptoms

This symptoms of this detection are the files, registry, and network communication referenced in the characteristics section.

Users being locked out of directory

Access to admin shares denied

Scheduled tasks being created

Access to security related web sites is blocked.

 

Method of Infection

This worm exploits the MS08-067 Microsoft Windows Server Service vulnerability in order to propagate.

Machines should be patched and rebooted to protect against this worm re-infecting the system after cleaning.

Upon detection of this worm the system should be rebooted to clean memory correctly. May require more that one reboot.

Scheduled tasks have been seen to be created on the system to re-activate the worm.

Autorun.inf files have been seen to be used to re-activate the worm.

 

 

 

 

Removal

Users infected by W32/Conficker.worm should perform an On Demand Scan to remove remnants of the worm in memory using the latest DATs.

Upon detection of W32/Conficker!mem and REBOOT, the W32/Conficker.worm malware components will be removed.

 

Variants

Variants

    N/A

All Information

Overview -

----Update on March 10, 2009---

The risk assessment of this threat has been updated to Low-Profiled due to media attention at

http://www.thetechherald.com/article.php/200911/3157/Conficker-Worm-fighting-back-a-new-variant-discovered-disables-security-measures

This detection is for a worm that exploits the MS08-067 vulnerability in order to spread. It may also download and execute various files onto the affected system.

Aliases

  • Worm:Win32/Conficker.A (Microsoft)
  • Crypt.AVL (AVG)
  • Mal/Conficker-A (Sophos)
  • Trojan.Win32.Pakes.lxf (F-Secure)
  • Trojan.Win32.Pakes.lxf (Kaspersky)
  • W32.Downadup (Symantec)
  • Worm:Win32/Conficker.B (Microsoft)
  • WORM_DOWNAD.A (Trend Micro)

Characteristics

Characteristics -

-----Updated on Nov 22 , 2011-----------

Aliases -

  • Kaspersky - Net-Worm.Win32.Kido.ih
  • NOD32 - a variant of Win32/Conficker.X
  • Ikarus - Net-Worm.Win32.Kido
  • Microsoft - Worm:Win32/Conficker.B

The following file has been added to the system.

  • [Removable Drive:]\RECYCLER\S-5-[varies]\jwgkvsq.vmx

The malware also drops an autorun.inf file into the root of all removable drives and mapped drives in an attempt to autorun an executable when the drive is accessed.

The file "AutoRun.inf" is pointing to the malware binary executable. When the removable or networked drive is accessed from a machine supporting the Autorun feature, the malware is launched automatically.

The following registry keys have been added to the system.

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\fuuomyu
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\safqdqya

The following registry value has been added to the system.

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List\
    4317 = TCP = "4317:TCP:*:Enabled:sdzcw"

The following registry values have been modified .

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RSVP\Parameters\StartBlocker = "Global\_RAPI_EVENT_NAME-C3E99E67-3B98-4E7E-91DAB5734F70E6ED"
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RSVP\Parameters\StartBlocker = ""
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RSVP\Parameters\Requests = "RAPIRpc Main-E17294EF-D5EC-40C0-B14DC2CDD7129511"
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RSVP\Parameters\Requests = ""
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RSVP\Parameters\Upcalls = "RAPIRpc Thread-6C1FCF96-AA8F-4B79-8A11E01958C1A170"
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RSVP\Parameters\Upcalls = ""

---------------------

----Update on March 10, 2009---

The risk assessment of this threat has been updated to Low-Profiled due to media attention at

http://www.thetechherald.com/article.php/200911/3157/Conficker-Worm-fighting-back-a-new-variant-discovered-disables-security-measures

A new variant of W32/Conficker.worm has been seen spreading.  It copies itself to the following pathes:

  • %Sysdir%\[Random].dll
  • %Program Files%\Internet Explorer\[Random].dll
  • %Program Files%\Movie Maker\[Random].dll
  • %Program Files%\Windows Media Player\[Random].dll
  • %Program Files%\Windows NT\[Random].dll

It disables the following services:

  • WerSvc
  • ERSvc
  • BITS
  • wuauserv
  • WinDefend
  • wscsvc

It hooks the following functions in dnsapi.dll :

  • Query_Main
  • DnsQuery_W
  • DnsQuery_UTF8
  • DnsQuery_A

It hooks the following functions in ws2_32.dll:

  • sendto

The worm deletes the following registry key to disable restarting in safe mode:

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SafeBoot

It deletes the following registry keys:

  • HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\explorer\ShellServiceObjects\{FD6905CE-952F-41F1-9A6F-135D9C6622CC}
  • HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run\Windows Defender

It terminates the processes that contains the following strings in name:

  • wireshark
  • unlocker
  • tcpview
  • sysclean
  • scct_
  • regmon
  • procmon
  • procexp
  • ms08-06
  • mrtstub
  • mrt.
  • mbsa.
  • klwk
  • kido
  • kb958
  • kb890
  • hotfix
  • gmer
  • filemon
  • downad
  • confick
  • avenger
  • autoruns

In order to block users access to security-related domains, prevents network access to any domains that contain the following strings:

  • windowsupdate
  • wilderssecurity
  • virus
  • virscan
  • trojan
  • trendmicro
  • threatexpert
  • threat
  • technet
  • symantec
  • sunbelt
  • spyware
  • spamhaus
  • sophos
  • secureworks
  • securecomputing
  • safety.live
  • rootkit
  • rising
  • removal
  • quickheal
  • ptsecurity
  • prevx
  • pctools
  • panda
  • onecare
  • norton
  • norman
  • nod32
  • networkassociates
  • mtc.sri
  • msmvps
  • msftncsi
  • mirage
  • microsoft
  • mcafee
  • malware
  • kaspersky
  • k7computing
  • jotti
  • ikarus
  • hauri
  • hacksoft
  • hackerwatch
  • grisoft
  • gdata
  • freeav
  • free-av
  • fortinet
  • f-secure
  • f-prot
  • ewido
  • etrust
  • eset
  • esafe
  • emsisoft
  • dslreports
  • drweb
  • defender
  • cyber-ta
  • cpsecure
  • conficker
  • computerassociates
  • comodo
  • clamav
  • centralcommand
  • ccollomb
  • castlecops
  • bothunter
  • avira
  • avgate
  • avast
  • arcabit
  • antivir
  • anti-
  • ahnlab
  • agnitum

The latest Conficker is known to generate 50,000 domain names using its own generator algorithm. The following is its disassembly snapshot.

The following suffixes are appended to any generated domains. It uses 116 different suffixes for example:

  • com.ve
  • com.uy
  • com.ua
  • com.tw
  • com.tt
  • com.tr
  • com.sv
  • com.py
  • com.pt
  • com.pr
  • com.pe
  • com.pa
  • com.ni
  • com.ng
  • com.mx
  • com.mt
  • com.lc
  • com.ki
  • com.jm
  • com.hn
  • com.gt
  • com.gl
  • com.gh
  • com.fj
  • com.do
  • com.co
  • com.bs
  • com.br
  • com.bo
  • com.ar
  • com.ai
  • com.ag
  • co.za
  • co.vi
  • co.uk
  • co.ug
  • co.nz
  • co.kr
  • co.ke
  • co.il
  • co.id
  • co.cr

-------------------------------------------------------------

When executed, the worm copies itself using a random name to the %Sysdir% folder.

(Where %Sysdir% is the Windows system folder; e.g. C:\Windows\System32)

It modifies the following registry key to create a randomly-named service on the affected syetem:

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\{random}\Parameters\"ServiceDll" = "Path to worm"
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\{random}\"ImagePath" = %SystemRoot%\system32\svchost.exe -k netsvcs

Attempts connections to one or more of the following websites to obtain the public ip address of the affected computer.

  • hxxp://www.getmyip.org
  • hxxp://getmyip.co.uk
  • hxxp://checkip.dyndns.org
  • hxxp://whatsmyipaddress.com

Attempts to download a malware file from the remote website: (Rogue Russian site is up but not serving file anymore)

  • hxxp://trafficconverter.biz/[Removed]antispyware/[Removed].exe

Starts a HTTP server on a random port on the infected machine to host a copy of the worm.

Continuously scans the subnet of the infected host for vulnerable machines and executes the exploit. If the exploit is successful, the remote computer will then connect back to the http server and download a copy of the worm.

Later variants of w32/Conficker.worm are using scheduled tasks and Autorun.inf file to replicate on to non vulnerable systems or to reinfect previously infected systems after they have been cleaned.

Symptoms

Symptoms -

This symptoms of this detection are the files, registry, and network communication referenced in the characteristics section.

Users being locked out of directory

Access to admin shares denied

Scheduled tasks being created

Access to security related web sites is blocked.

 

Method of Infection

Method of Infection -

This worm exploits the MS08-067 Microsoft Windows Server Service vulnerability in order to propagate.

Machines should be patched and rebooted to protect against this worm re-infecting the system after cleaning.

Upon detection of this worm the system should be rebooted to clean memory correctly. May require more that one reboot.

Scheduled tasks have been seen to be created on the system to re-activate the worm.

Autorun.inf files have been seen to be used to re-activate the worm.

 

 

 

 

Removal -

Removal -

Users infected by W32/Conficker.worm should perform an On Demand Scan to remove remnants of the worm in memory using the latest DATs.

Upon detection of W32/Conficker!mem and REBOOT, the W32/Conficker.worm malware components will be removed.

 

Variants

Variants -

    N/A