Worm.Win32.Ainslot.VB_e129db9f81

Dynamic Analysis

Payload

Behaviour	Description
WormAutorun	A worm can spread via removable drives. It writes its executable and creates "autorun.inf" scripts on all removable drives. The autorun script will execute the Worm's file once a user opens a drive's folder in Windows Explorer.

Process activity

The Worm creates the following process(es):

explor.exe:1504
WScript.exe:988
%original file name%.exe:1456
rundll32.exe:204
reg.exe:1568
reg.exe:1360
reg.exe:1584
reg.exe:516
dumprep.exe:296
dumprep.exe:888

The Worm injects its code into the following process(es):No processes have been created.

File activity

The process explor.exe:1504 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\1.vbs (893 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Tar2.tmp (2712 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Cab5.tmp (54 bytes)
%Documents and Settings%\%current user%\Application Data\Microsoft\CryptnetUrlCache\MetaData\2BF68F4714092295550497DD56F57004 (408 bytes)
%Documents and Settings%\%current user%\Application Data\Microsoft\CryptnetUrlCache\Content\94308059B57B3142E455B38A6EB92015 (54 bytes)
%Documents and Settings%\%current user%\Application Data\Microsoft\CryptnetUrlCache\MetaData\94308059B57B3142E455B38A6EB92015 (408 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Cab1.tmp (49 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Tar6.tmp (2712 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Tar4.tmp (2712 bytes)
%Documents and Settings%\%current user%\Application Data\Microsoft\CryptnetUrlCache\Content\2BF68F4714092295550497DD56F57004 (18 bytes)
%Documents and Settings%\%current user%\Application Data\DataWork\explor.exe (2105 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Cab3.tmp (49 bytes)

The Worm deletes the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temp\Tar2.tmp (0 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Cab5.tmp (0 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Cab1.tmp (0 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Tar6.tmp (0 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Tar4.tmp (0 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Cab3.tmp (0 bytes)

The process WScript.exe:988 makes changes in the file system.

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

%Documents and Settings%\%current user%\Application Data\Sample.lnk (788 bytes)

The Worm deletes the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temp\1.vbs (0 bytes)

The process %original file name%.exe:1456 makes changes in the file system.

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

%Documents and Settings%\%current user%\Application Data\explor.exe (50052 bytes)

The process dumprep.exe:296 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\WER8070.dir00\svchost.exe.hdmp (224815 bytes)

The process dumprep.exe:888 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\WER8070.dir00\svchost.exe.mdmp (105843 bytes)

Registry activity

The process explor.exe:1504 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "3C 11 10 63 0C C5 D3 E1 99 64 5E 68 48 FF 4B 2C"

[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\S]
"E" = "1"

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

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

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

[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"

[HKCU\Software\Microsoft\Windows\ShellNoRoam\MUICache\%WinDir%\System32]
"WScript.exe" = "Microsoft (R) Windows Based Script Host"

[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 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 urls to the Intranet Zone:

"IntranetName" = "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 WScript.exe:988 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "EE 8F 59 62 5C E2 01 6A 5E E4 F0 C5 45 F8 8C 0F"

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

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

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

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

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

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

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

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

[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"

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

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

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

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\RunOnce]
"sidebar" = "%Documents and Settings%\%current user%\Application Data\Sample.lnk"

The process %original file name%.exe:1456 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "EF C0 5E 37 84 71 15 74 B6 1A 6A 18 58 1A FF F5"

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

The process rundll32.exe:204 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "BE 31 28 22 34 A7 50 4A 06 B3 65 BD A4 B6 95 00"

[HKCU\Software\Microsoft\Windows\ShellNoRoam\MUICache\%System%]
"svchost.exe" = "Generic Host Process for Win32 Services"

[HKLM\System\CurrentControlSet\Control\Session Manager\AppCompatibility]
"AppCompatCache" = "EF BE AD DE 60 00 00 00 00 00 00 00 00 00 00 00"

[HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers\%System%]
"svchost.exe" = "EnableNXShowUI"

The process reg.exe:1568 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "AB 5F 0A D5 F8 97 E0 CD 0B 5B A5 C1 81 20 FF 08"

[HKLM\System\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile]
"DoNotAllowExceptions" = "0"

The process reg.exe:1360 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "D0 94 F1 F0 16 CE 9D DE 0E 81 8F 70 B0 33 F3 6B"

Adds a rule to the firewall Windows which allows any network activity:

[HKLM\System\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List\%Documents and Settings%\%current user%\Application Data\Microsoft]
"2.exe" = "%Documents and Settings%\%current user%\Application Data\Microsoft\2.exe:*:Enabled:Windows Messanger"

The process reg.exe:1584 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "A4 F5 39 89 0B BE DA 95 55 8D 39 0B 9A 5A F4 21"

Adds a rule to the firewall Windows which allows any network activity:

[HKLM\System\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List\%System%]
"svchost.exe" = "%System%\svchost.exe:*:Enabled:Windows Messanger"

The process reg.exe:516 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "E5 8F EB 9E E6 0D 53 75 A4 44 CB CC 25 5C 8D 8A"

[HKLM\System\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile]
"DoNotAllowExceptions" = "0"

The process dumprep.exe:296 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "18 99 A9 7A 60 3C 8F 1D 55 8D D8 FE D9 9F E4 F6"

The process dumprep.exe:888 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "3F 9E AA BD 73 37 3B 93 9D 0A 11 9B EB 09 66 0A"

Network activity (URLs)

URL	IP
hxxp://tazbox.zapto.org/downloader/serv.exe (Malicious)	31.6.35.84
hxxp://a26.d.akamai.net/msdownload/update/v3/static/trustedr/en/authrootseq.txt
hxxp://a26.d.akamai.net/msdownload/update/v3/static/trustedr/en/authrootstl.cab
www.download.windowsupdate.com	165.254.155.26

HOSTS file anomalies

No changes have been detected.

Rootkit activity

No anomalies have been detected.

Propagation

A worm can spread via removable drives. It writes its executable and creates "autorun.inf" scripts on all removable drives. The autorun script will execute the Worm's file once a user opens a drive's folder in Windows Explorer.

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. Terminate malicious process(es) (How to End a Process With the Task Manager):

   explor.exe:1504
   WScript.exe:988
   %original file name%.exe:1456
   rundll32.exe:204
   reg.exe:1568
   reg.exe:1360
   reg.exe:1584
   reg.exe:516
   dumprep.exe:296
   dumprep.exe:888

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

   %Documents and Settings%\%current user%\Local Settings\Temp\1.vbs (893 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\Tar2.tmp (2712 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\Cab5.tmp (54 bytes)
   %Documents and Settings%\%current user%\Application Data\Microsoft\CryptnetUrlCache\MetaData\2BF68F4714092295550497DD56F57004 (408 bytes)
   %Documents and Settings%\%current user%\Application Data\Microsoft\CryptnetUrlCache\Content\94308059B57B3142E455B38A6EB92015 (54 bytes)
   %Documents and Settings%\%current user%\Application Data\Microsoft\CryptnetUrlCache\MetaData\94308059B57B3142E455B38A6EB92015 (408 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\Cab1.tmp (49 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\Tar6.tmp (2712 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\Tar4.tmp (2712 bytes)
   %Documents and Settings%\%current user%\Application Data\Microsoft\CryptnetUrlCache\Content\2BF68F4714092295550497DD56F57004 (18 bytes)
   %Documents and Settings%\%current user%\Application Data\DataWork\explor.exe (2105 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\Cab3.tmp (49 bytes)
   %Documents and Settings%\%current user%\Application Data\Sample.lnk (788 bytes)
   %Documents and Settings%\%current user%\Application Data\explor.exe (50052 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\WER8070.dir00\svchost.exe.hdmp (224815 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\WER8070.dir00\svchost.exe.mdmp (105843 bytes)

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

   [HKCU\Software\Microsoft\Windows\CurrentVersion\RunOnce]
   "sidebar" = "%Documents and Settings%\%current user%\Application Data\Sample.lnk"

5. Clean the Temporary Internet Files folder, which may contain infected files (How to clean Temporary Internet Files folder).
   
6. Find and delete all copies of the worm's file together with "autorun.inf" scripts on removable drives.
   
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