Worm.Win32.Ainslot_VariantOfZeus_87e4d2c37e

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):

%original file name%.exe:1620
reg.exe:1436
reg.exe:1652
reg.exe:1584
reg.exe:480

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

vbc.exe:460

File activity

The process %original file name%.exe:1620 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\windows.exe (1755 bytes)

The process vbc.exe:460 makes changes in the file system.

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

%Documents and Settings%\%current user%\Application Data\keylog (34 bytes)

Registry activity

The process %original file name%.exe:1620 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "FE 45 E7 B5 9B 33 BF 94 C1 59 B3 35 D0 F0 8D 5E"

[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]
"Windows Firewall" = "C:\DOCUME~1\"%CurrentUserName%"\LOCALS~1\Temp\windows.exe"

The process vbc.exe:460 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "03 97 3F 25 5F 68 95 3F CB 23 E0 F0 15 98 C1 B2"

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

[HKCU\Software\VB and VBA Program Settings\INSTALL\DATE]
"C2TOTT8R9U" = "November 13, 2013"

[HKCU\Software\VB and VBA Program Settings\SrvID\ID]
"C2TOTT8R9U" = "abc's Bot"

The process reg.exe:1436 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "F4 22 B2 0A 7C 6E 71 32 63 8B 41 B1 27 37 98 E9"

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

The process reg.exe:1652 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "1A 36 62 BA B7 83 4D 01 CB B5 B1 61 9F 33 BD B2"

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 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" = "D1 39 63 75 5B 21 0E 25 97 E8 F4 47 14 42 C9 B2"

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

The process reg.exe:480 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "9E 95 1A A5 AE 6C EF C4 F3 B2 F7 7A 5C 23 DF 2E"

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]
"Z1M0I7BUYF.exe" = "%Documents and Settings%\%current user%\Application Data\Z1M0I7BUYF.exe:*:Enabled:Windows Messanger"

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):

   %original file name%.exe:1620
   reg.exe:1436
   reg.exe:1652
   reg.exe:1584
   reg.exe:480

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\windows.exe (1755 bytes)
   %Documents and Settings%\%current user%\Application Data\keylog (34 bytes)

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

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