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Worm.Win32.Vobfus.11_7777c97a59


Trojan.Win32.Chifrax.cma (Kaspersky), Trojan.Win32.Generic.pak!cobra (VIPRE), Trojan-Dropper.Win32.TDSS!IK (Emsisoft), Worm.Win32.Vobfus.11.FD, Tdl4.YR (Lavasoft MAS)Behaviour: Trojan-Dropper, Trojan, Worm

The description has been automatically generated by Lavasoft Malware Analysis System and it may contain incomplete or inaccurate information.

Summary

MD5: 7777c97a592fac5e1d9ae731286b2d42

SHA1: a912dd3ee7a4508a4b26e271cbcce9a0cbb5f8da

SHA256: 4475fb8c642640097cfb590163c3f70b8f1ef2c1fde5cff7ec280ac7efddbed6

SSDeep: 12288:o/6sYNcry2VJF0DCY7XxgIQ2lTQmJ/AUkWsTfuUKVpyOQ5fNB:DF7pzJ/RwGUFFzB

Size: 525070 bytes

File type: PE32

Platform: WIN32

Entropy: Packed

PEID: MicrosoftVisualC; Armadillov171; MicrosoftVisualCv50v60MFC; MicrosoftVisualC50; UPolyXv05_v6

Company: no certificate found

Created at: 2011-05-08 20:22:30

Summary: Trojan-Dropper. Trojan program, intended for stealth installation of other malware into user's system.

Dynamic Analysis

Process activity

The Worm creates the following process(es):

i.exe:1944
tasklist.exe:1660
j.exe:828
hfZt1ljDOw.exe:488
7777c97a592fac5e1d9ae731286b2d42.exe:1304

The Worm injects its code into the following process(es):

spoolsv.exe:1440
mwdav.exe:1580

File activity

The process i.exe:1944 makes changes in a file system.


The Worm creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temp\2.tmp (673 bytes)

The Worm deletes the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temp\3.tmp (0 bytes)

The process spoolsv.exe:1440 makes changes in a file system.


The Worm creates and/or writes to the following file(s):

%WinDir%\Temp\4.tmp (20 bytes)

The Worm deletes the following file(s):

%WinDir%\Temp\4.tmp (0 bytes)
%System%\drivers\etc\hosts (0 bytes)

The process j.exe:828 makes changes in a file system.


The Worm creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temp\Scv..bat (140 bytes)

The process hfZt1ljDOw.exe:488 makes changes in a file system.


The Worm creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\mwdav.exe (1969690 bytes)

The process 7777c97a592fac5e1d9ae731286b2d42.exe:1304 makes changes in a file system.


The Worm creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\i.exe (628 bytes)
%Documents and Settings%\%current user%\j.exe (510 bytes)
%Documents and Settings%\%current user%\hfZt1ljDOw.exe (267 bytes)

The Worm deletes the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temp\7zS1.tmp (0 bytes)

Registry activity

The process i.exe:1944 makes changes in a system registry.


The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "6F D5 E0 AA 6D 65 23 14 F9 D0 E2 D0 7E 8F 3B BD"

[HKLM\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication]
"ID" = "1304845567"

[HKLM\System\CurrentControlSet\Control\Session Manager]
"PendingFileRenameOperations" = "\??\C:\DOCUME~1\"%CurrentUserName%"\LOCALS~1\Temp\5.tmp,"

[HKLM\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication]
"Name" = "i.exe"

The process tasklist.exe:1660 makes changes in a system registry.


The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "99 A5 9A 80 AE 91 B1 BA 18 F3 0F EF 39 F0 1B 94"

The process spoolsv.exe:1440 makes changes in a system registry.


The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication]
"ID" = "1208114401"

[HKLM\System\CurrentControlSet\Control\Session Manager]
"PendingFileRenameOperations" = "\??\C:\DOCUME~1\"%CurrentUserName%"\LOCALS~1\Temp\5.tmp, , \??\%WinDir%\TEMP\6.tmp,"

[HKLM\System\CurrentControlSet\Control\Print\Providers\3264580096]
"Name" = "C:\DOCUME~1\"%CurrentUserName%"\LOCALS~1\Temp\3.tmp"

[HKLM\System\CurrentControlSet\Services\d30ba3c0]
"imagepath" = "\??\%WinDir%\TEMP\4.tmp"

[HKLM\System\CurrentControlSet\Services\d30ba3c0]
"type" = "1"

[HKLM\System\CurrentControlSet\Control\Print\Providers]
"Order" = "LanMan Print Services, Internet Print Provider, 3264580096"

[HKLM\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication]
"Name" = "spoolsv.exe"

The Worm deletes the following registry key(s):

[HKLM\System\CurrentControlSet\Services\d30ba3c0]
[HKLM\System\CurrentControlSet\Services\d30ba3c0\Enum]
[HKLM\System\CurrentControlSet\Control\Print\Providers\3264580096]

The process j.exe:828 makes changes in a system registry.


The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths]
"Directory" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path4]
"CacheLimit" = "65452"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path4]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache4"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Personal" = "%Documents and Settings%\%current user%\My Documents"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd73-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Cookies" = "%Documents and Settings%\%current user%\Cookies"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path2]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache2"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd75-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Common Desktop" = "%Documents and Settings%\All Users\Desktop"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Cache" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Desktop" = "%Documents and Settings%\%current user%\Desktop"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Common Documents" = "%Documents and Settings%\All Users\Documents"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path1]
"CacheLimit" = "65452"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Zones\]
"1806" = "0"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path2]
"CacheLimit" = "65452"

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "B2 7A 13 21 55 45 59 D6 2B 6C 03 4B B1 6C 4E A7"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path1]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache1"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path3]
"CacheLimit" = "65452"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd72-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{b98117e8-75ca-11e2-81b2-000c293708fb}]
"BaseClass" = "Drive"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path3]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache3"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths]
"Paths" = "4"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"History" = "%Documents and Settings%\%current user%\Local Settings\History"

The Worm modifies IE settings for security zones to map all local web-nodes with no dots which do not refer to any zone to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"UNCAsIntranet" = "1"

The Worm modifies IE settings for security zones to map all web-nodes that bypassing proxy to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"ProxyBypass" = "1"

The Worm modifies IE settings for security zones to map all urls to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"IntranetName" = "1"

The process mwdav.exe:1580 makes changes in a system registry.


The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "45 E8 29 EF 8D 89 5C 39 13 71 D7 32 9D 9F F8 2E"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced]
"ShowSuperHidden" = "0"

To automatically run itself each time Windows is booted, the Worm adds the following link to its file to the system registry autorun key:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
"mwdav" = "%Documents and Settings%\%current user%\mwdav.exe /z"

The process hfZt1ljDOw.exe:488 makes changes in a system registry.


The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "93 5E 53 41 3B 8F EF 54 CA 6E 05 47 76 F0 65 27"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd73-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Cookies" = "%Documents and Settings%\%current user%\Cookies"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Common Documents" = "%Documents and Settings%\All Users\Documents"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Desktop" = "%Documents and Settings%\%current user%\Desktop"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd72-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{b98117e8-75ca-11e2-81b2-000c293708fb}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Cache" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Common Desktop" = "%Documents and Settings%\All Users\Desktop"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd75-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\ShellNoRoam\MUICache\%Documents and Settings%\%current user%]
"mwdav.exe" = "mwdav"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders]
"Personal" = "%Documents and Settings%\%current user%\My Documents"

The Worm modifies IE settings for security zones to map all urls to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"IntranetName" = "1"

The Worm modifies IE settings for security zones to map all local web-nodes with no dots which do not refer to any zone to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"UNCAsIntranet" = "1"

The Worm modifies IE settings for security zones to map all web-nodes that bypassing proxy to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"ProxyBypass" = "1"

The process 7777c97a592fac5e1d9ae731286b2d42.exe:1304 makes changes in a system registry.


The Worm creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "5E C6 46 B1 84 C0 CF E4 EC A9 7A E9 31 8F 4F FA"

Network activity (URLs)

No activity has been detected.

Rootkit activity

Using the driver "UNKNOWN" the Worm controls loading executable images into a memory by installing the Load image notifier.



The Worm intercepts DriverStartIO in a miniport driver of a hard drive controller (ATAPI) to handle request to its own files:

StartIo

Propagation

Removals

Remove it with Ad-Aware

  1. Click (here) to download and install Ad-Aware Free Antivirus.
  2. Update the definition files.
  3. Run a full scan of your computer.

Manual removal*

  1. Scan a system with an anti-rootkit tool.
  2. Terminate malicious process(es) (How to End a Process With the Task Manager):

    i.exe:1944
    tasklist.exe:1660
    j.exe:828
    hfZt1ljDOw.exe:488
    7777c97a592fac5e1d9ae731286b2d42.exe:1304

  3. Delete the original Worm file.
  4. Delete or disinfect the following files created/modified by the Worm:

    %Documents and Settings%\%current user%\Local Settings\Temp\2.tmp (673 bytes)
    %WinDir%\Temp\4.tmp (20 bytes)
    %Documents and Settings%\%current user%\Local Settings\Temp\Scv..bat (140 bytes)
    %Documents and Settings%\%current user%\mwdav.exe (1969690 bytes)
    %Documents and Settings%\%current user%\i.exe (628 bytes)
    %Documents and Settings%\%current user%\j.exe (510 bytes)
    %Documents and Settings%\%current user%\hfZt1ljDOw.exe (267 bytes)

  5. Delete the following value(s) in the autorun key (How to Work with System Registry):

    [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
    "mwdav" = "%Documents and Settings%\%current user%\mwdav.exe /z"

  6. Reboot the computer.
*Manual removal may cause unexpected system behaviour and should be performed at your own risk.

Static Analysis

Network Activity

Map

Strings from Dumps