Threat Description

Virus:​W32/Alman.B

Details

Aliases: Virus.Win32.Alman.b, Win32.almanahe.b, Alman.b
Category: Malware
Type: Net-Worm, Rootkit
Platform: W32

Summary



A program that secretly and maliciously integrates itself into program or data files. It spreads by integrating itself into more files each time the host program is run.



Removal



Manual Network Disinfection

Alman.B is a network virus/worm with rootkit features, so it requires specific disinfection instructions:

  • Stop all network sharing or completely disconnect from the network
  • Set disinfection action for real-time scanner to "Disinfect Automatically"
  • Perform a full computer scan with F-Secure Anti-Virus
  • Select "Disinfect" action for all infected files
  • Files that can not be disinfected should be quarantined or deleted (select appropriate action manually)
  • Files dropped by the virus: "linkinfo.dll", "nvmini.sys" and "IsDrv118.sys" should be deleted or quarantined
  • Broken infected files should be restored from a backup
  • After disinfection restart a computer
  • After restart perform a full scan again to make sure that no infection is left
  • Enable sharing or reconnect the network ONLY after ALL computers are disinfected, otherwise a single infected workstation can re-infect the whole network
  • Make sure that all network shares have strong passwords
  • After disinfection set the default disinfection action for real-time scanner to "Ask After Scan" if needed


Technical Details



Virus:W32/Alman.B infects all executable files in the system. The virus propagates over a network. It also has rootkit capabilities.

An earlier variant of this virus, Virus:W32/Alman.A, is also in the wild.

Variants of this family may be detected by the Generic Detection, Virus:W32/Alman.gen!A.

Infection

The virus infects EXE files that are not protected by Windows System File Check on local, removable, and remote drives. The virus does not infect files with these names:

  • asktao.exe
  • au_unins_web.exe
  • audition.exe
  • autoupdate.exe
  • ca.exe
  • cabal.exe
  • cabalmain.exe
  • cabalmain9x.exe
  • config.exe
  • dbfsupdate.exe
  • dk2.exe
  • dragonraja.exe
  • flyff.exe
  • game.exe
  • gc.exe
  • hs.exe
  • kartrider.exe
  • main.exe
  • maplestory.exe
  • meteor.exe
  • mhclient-connect.exe
  • mjonline.exe
  • mts.exe
  • nbt-dragonraja2006.exe
  • neuz.exe
  • nmcosrv.exe
  • nmservice.exe
  • nsstarter.exe
  • patcher.exe
  • patchupdate.exe
  • sealspeed.exe
  • trojankiller.exe
  • userpic.exe
  • wb-service.exe
  • woool.exe
  • wooolcfg.exe
  • xlqy2.exe
  • xy2.exe
  • xy2player.exe
  • zfs.exe
  • zhengtu.exe
  • ztconfig.exe
  • zuonline.exe

The virus also doesn't infect files located in the following folders:

  • \LOCAL SETTINGS\TEMP\
  • \QQ
  • \WINDOWS\
  • \WINNT\

Payload

After the infected file is started the virus decrypts its body and drops two files:

  • %WinDir%\linkinfo.dll
  • %WinSysDir%\drivers\IsDrv118.sys

The DLL is the main virus component. The SYS file is a rootkit component that hides certain files and Registry keys.

The dropped DLL file is injected into Windows Explorer process and runs with system privileges.

The virus terminates the following processes:

  • c0nime.exe
  • cmdbcs.exe
  • ctmontv.exe
  • explorer.exe
  • fuckjacks.exe
  • iexpl0re.exe
  • iexpl0re.exe
  • iexplore.exe
  • internat.exe
  • logo_1.exe
  • logo1_.exe
  • lsass.exe
  • lying.exe
  • msdccrt.exe
  • msvce32.exe
  • ncscv32.exe
  • nvscv32.exe
  • realschd.exe
  • rpcs.exe
  • run1132.exe
  • rundl132.exe
  • smss.exe
  • spo0lsv.exe
  • spoclsv.exe
  • ssopure.exe
  • svch0st.exe
  • svhost32.exe
  • sxs.exe
  • sysbmw.exe
  • sysload3.exe
  • tempicon.exe
  • upxdnd.exe
  • wdfmgr32.exe
  • wsvbs.exe

If the files that belong to terminated processes are located in specific folders, they are deleted.

Propagation

To spread in a network the virus tries to connect to the IPC$ share with login "Administrator" and performs a dictionary attack on the admin password using these values:

  • admin
  • aaa
  • !@#$
  • asdf
  • asdfgh
  • !@#$%
  • !@#$%^
  • !@#$%^&
  • !@#$%^&*
  • !@#$%^&*(
  • !@#$%^&*()
  • qwer
  • admin123
  • love
  • test123
  • owner
  • mypass123
  • root
  • letmein
  • qwerty
  • abc123
  • password
  • monkey
  • password1
  • 1
  • 111
  • 123
  • 12345
  • 654321
  • 123456789

If connection is successful, the virus copies itself as "Setup.exe" file to the root of the system drive and starts the copied file as a service.



Detection


F-Secure Anti-Virus detects this malware with the following updates:
Detection Type: PC
Database: 2007-06-06_03




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