Worm.Win32.Vobfus.11_0557e137b4

Dynamic Analysis

Payload

No specific payload has been found.

Process activity

The Worm creates the following process(es):

vobfuz.exe:528
TBetLh8vyV2cc7y4N8.exe:448
wobfud.exe:872
%original file name%.exe:1308
vobfux.exe:444
tasklist.exe:1056

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

qrwiuv.exe:1680
spoolsv.exe:1424

File activity

The process TBetLh8vyV2cc7y4N8.exe:448 makes changes in the file system.

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

%Documents and Settings%\%current user%\qrwiuv.exe (2013107 bytes)

The process wobfud.exe:872 makes changes in the file system.

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

%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\desktop.ini (67 bytes)

The process %original file name%.exe:1308 makes changes in the file system.

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

%Documents and Settings%\%current user%\vobfuz.exe (1923 bytes)
%Documents and Settings%\%current user%\wobfud.exe (1125 bytes)
%Documents and Settings%\%current user%\TBetLh8vyV2cc7y4N8.exe (403 bytes)
%Documents and Settings%\%current user%\vobfux.exe (1309 bytes)

The Worm deletes the following file(s):

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

The process vobfux.exe:444 makes changes in the 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:1424 makes changes in the file system.

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

%WinDir%\Temp\4.tmp (43 bytes)

The Worm deletes the following file(s):

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

Registry activity

The process vobfuz.exe:528 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "3A C6 2C 0F D9 D7 F5 C2 92 33 54 11 25 2F E5 B3"

The process TBetLh8vyV2cc7y4N8.exe:448 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "AE 04 CC 35 94 3D EA 46 05 D3 3B 9F C2 C4 DA 44"

[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%]
"qrwiuv.exe" = "qrwiuv"

[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:

"UNCAsIntranet" = "1"

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

"ProxyBypass" = "1"

The process qrwiuv.exe:1680 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "3D 7E D9 92 8D F8 1D 57 E8 23 21 4B 53 D0 00 55"

[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]
"qrwiuv" = "%Documents and Settings%\%current user%\qrwiuv.exe /A"

The process wobfud.exe:872 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "DE C0 58 AA 4D FD 60 33 96 CF 6F 3E 30 DF ED 34"

[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"

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

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

[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\{b98117e8-75ca-11e2-81b2-000c293708fb}]
"BaseClass" = "Drive"

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

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

[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"
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache4"

[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\MountPoints2\{c155cd75-744b-11e2-8294-806d6172696f}]
"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\Internet Settings\Cache\Paths\path2]
"CacheLimit" = "65452"

The process %original file name%.exe:1308 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "75 46 6E 27 81 1A 4F 97 B0 AD D4 B3 5F EA 4C F1"

The process vobfux.exe:444 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "6F 83 2F 9F A3 71 C2 B7 8C FE CE A8 38 29 96 A9"

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

The process spoolsv.exe:1424 makes changes in the system registry.

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

[HKLM\System\CurrentControlSet\Services\8e26fce0]
"imagepath" = "\??\%WinDir%\TEMP\4.tmp"
"type" = "1"

[HKLM\System\CurrentControlSet\Control\Print\Providers\2667345304]
"Name" = "C:\DOCUME~1\"%CurrentUserName%"\LOCALS~1\Temp\3.tmp"

[HKLM\System\CurrentControlSet\Control\Print\Providers]
"Order" = "LanMan Print Services, Internet Print Provider, 2667345304"

The Worm deletes the following registry key(s):

[HKLM\System\CurrentControlSet\Services\8e26fce0]
[HKLM\System\CurrentControlSet\Services\8e26fce0\Enum]
[HKLM\System\CurrentControlSet\Control\Print\Providers\2667345304]

The process tasklist.exe:1056 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "06 60 02 4D 39 EB 2E 46 67 A6 3B 5B C0 F6 86 F7"

Network activity (URLs)

URL	IP
daletter.com	Unresolvable

HOSTS file anomalies

No changes have 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):

   vobfuz.exe:528
   TBetLh8vyV2cc7y4N8.exe:448
   wobfud.exe:872
   %original file name%.exe:1308
   vobfux.exe:444
   tasklist.exe:1056

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

   %Documents and Settings%\%current user%\qrwiuv.exe (2013107 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\desktop.ini (67 bytes)
   %Documents and Settings%\%current user%\vobfuz.exe (1923 bytes)
   %Documents and Settings%\%current user%\wobfud.exe (1125 bytes)
   %Documents and Settings%\%current user%\TBetLh8vyV2cc7y4N8.exe (403 bytes)
   %Documents and Settings%\%current user%\vobfux.exe (1309 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\2.tmp (673 bytes)
   %WinDir%\Temp\4.tmp (43 bytes)

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

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

6. Clean the Temporary Internet Files folder, which may contain infected files (How to clean Temporary Internet Files folder).
   
7. 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