Worm.Win32.Ainslot.VB_198bbd4ca9

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):

198bbd4ca9ec429ca0e8097120d85180.exe:1340
reg.exe:524
reg.exe:1260
reg.exe:1748
reg.exe:1504

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

vbc.exe:1796

File activity

The process 198bbd4ca9ec429ca0e8097120d85180.exe:1340 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\vbc.exe (7547 bytes)

The process vbc.exe:1796 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\Va.exe (3922 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\Rs (33 bytes)

Registry activity

The process 198bbd4ca9ec429ca0e8097120d85180.exe:1340 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "68 42 F4 64 54 E3 BF CD 06 90 D6 D0 71 34 DE B5"

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

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

The process reg.exe:524 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 E4 B1 00 96 CC BF 9D D2 35 6D 6F BC 4B C1 28"

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

[HKLM\System\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List\c:]
"198bbd4ca9ec429ca0e8097120d85180.exe" = "c:\198bbd4ca9ec429ca0e8097120d85180.exe:*:Enabled:Windows Messanger"

The process reg.exe:1260 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "A1 AC D3 A6 65 F7 4F 3C 17 5E 4F 37 FD 41 4C E7"

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

The process reg.exe:1748 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "1D 32 A2 4A 61 B0 06 57 C4 89 DC 1C D0 60 30 7E"

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

[HKLM\System\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List\C:\DOCUME~1\"%CurrentUserName%"\LOCALS~1\Temp]
"Va.exe" = "C:\DOCUME~1\"%CurrentUserName%"\LOCALS~1\Temp\Va.exe:*:Enabled:Windows Messanger"

The process reg.exe:1504 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "F5 AD 54 AE 13 E1 58 B3 D0 EE 46 B8 37 C4 EC 95"

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

The process vbc.exe:1796 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "86 91 BE C0 CB FC 28 73 D9 11 87 D9 78 7D 75 73"

[HKLM\SOFTWARE\Microsoft\Active Setup\Installed Components\{F9EFAFEA-AC8A-F1AB-2CBD-CBFEA4CCEC1A}]
"StubPath" = "C:\DOCUME~1\"%CurrentUserName%"\LOCALS~1\Temp\Va.exe"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\run]
"Windows Defender" = "C:\DOCUME~1\"%CurrentUserName%"\LOCALS~1\Temp\Va.exe"

[HKCU\Software\Microsoft\Active Setup\Installed Components\{F9EFAFEA-AC8A-F1AB-2CBD-CBFEA4CCEC1A}]
"StubPath" = "C:\DOCUME~1\"%CurrentUserName%"\LOCALS~1\Temp\Va.exe"

[HKCU\Software\VB and VBA Program Settings\SrvID\ID]
"W8Y9GFU73N" = "7/1/2001"

[HKCU\Software\VB and VBA Program Settings\INSTALL\DATE]
"W8Y9GFU73N" = "August 12, 2013"

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]
"Windows Defender" = "C:\DOCUME~1\"%CurrentUserName%"\LOCALS~1\Temp\Va.exe"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
"Windows Defender" = "C:\DOCUME~1\"%CurrentUserName%"\LOCALS~1\Temp\Va.exe"

Network activity (URLs)

No activity has 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):

   198bbd4ca9ec429ca0e8097120d85180.exe:1340
   reg.exe:524
   reg.exe:1260
   reg.exe:1748
   reg.exe:1504
   

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\vbc.exe (7547 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\Va.exe (3922 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\Rs (33 bytes)

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

   [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
   "Windows Defender" = "C:\DOCUME~1\"%CurrentUserName%"\LOCALS~1\Temp\Va.exe"
   
   [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
   "Windows Defender" = "C:\DOCUME~1\"%CurrentUserName%"\LOCALS~1\Temp\Va.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