Worm.Win32.Ainslot.VB_f02495821a

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):

reg.exe:824
reg.exe:504
reg.exe:1628
reg.exe:392
%original file name%.exe:596

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

vbc.exe:1164

File activity

The process vbc.exe:1164 makes changes in the file system.

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

%Documents and Settings%\%current user%\Application Data\4TSQ4H3FLC.exe (3860 bytes)
%Documents and Settings%\%current user%\Application Data\logs (35 bytes)

The process %original file name%.exe:596 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\WinDefender.Exe (3073 bytes)

Registry activity

The process vbc.exe:1164 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "C7 4F 7E A4 57 7B 10 3B 6B 5F 2E 93 B8 63 38 E5"

[HKCU\Software\VB and VBA Program Settings\INSTALL\DATE]
"P1YZ2EXU7Y" = "December 17, 2013"

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

[HKCU\Software\VB and VBA Program Settings\SrvID\ID]
"P1YZ2EXU7Y" = "Runescape"

The process reg.exe:824 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "01 B0 7F 27 59 9E 96 B5 25 53 02 4C C5 ED 1D 2D"

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

The process reg.exe:504 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "68 05 8A EA 2A 55 6F CC 3C C9 38 FF 3D D1 D6 AC"

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

The process reg.exe:1628 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "36 CC FA 84 78 BD 0E AE 20 7B 8C 6F E0 5C E2 29"

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]
"4TSQ4H3FLC.exe" = "%Documents and Settings%\%current user%\Application Data\4TSQ4H3FLC.exe:*:Enabled:Windows Messanger"

The process reg.exe:392 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "8A A6 B8 C0 4F 6E 09 A9 8D 05 8D 2C 0F B7 A8 67"

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

[HKLM\System\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List\%WinDir%\Microsoft.NET\Framework\v2.0.50727]
"vbc.exe" = "%WinDir%\Microsoft.NET\Framework\v2.0.50727\vbc.exe:*:Enabled:Windows Messanger"

The process %original file name%.exe:596 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "F2 78 E7 9F 07 C6 96 4B 6A 5C 99 AC 81 A1 8B 06"

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

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]
"WinDefender" = "C:\DOCUME~1\"%CurrentUserName%"\LOCALS~1\Temp\WinDefender.Exe"

Network activity (URLs)

No activity has been detected.

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):

   reg.exe:824
   reg.exe:504
   reg.exe:1628
   reg.exe:392
   %original file name%.exe:596

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

   %Documents and Settings%\%current user%\Application Data\4TSQ4H3FLC.exe (3860 bytes)
   %Documents and Settings%\%current user%\Application Data\logs (35 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\WinDefender.Exe (3073 bytes)

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

   [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
   "WinDefender" = "C:\DOCUME~1\"%CurrentUserName%"\LOCALS~1\Temp\WinDefender.Exe"

5. Find and delete all copies of the worm's file together with "autorun.inf" scripts on removable drives.
   
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