Worm.Win32.Ainslot_VariantOfZeus_75a0ac47db

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:480
rundll32.exe:132
reg.exe:2024
reg.exe:1064
reg.exe:1548
reg.exe:644
dumprep.exe:1852
dumprep.exe:1092

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

File activity

The process %original file name%.exe:480 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\svchost.exe (35 bytes)

The process dumprep.exe:1852 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\WERde8e.dir00\svchost.exe.hdmp (211564 bytes)

The process dumprep.exe:1092 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\WERde8e.dir00\svchost.exe.mdmp (102001 bytes)

Registry activity

The process %original file name%.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" = "F1 65 7D 70 E9 37 E3 04 5F 18 25 29 FE F3 BD 65"

[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 Live" = "c:\%original file name%.exe"

The process rundll32.exe:132 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "25 DC 51 D4 78 39 3B E7 4E 7A BD 90 83 65 67 A5"

[HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers\%Documents and Settings%\%current user%\Local Settings\Temp]
"svchost.exe" = "EnableNXShowUI"

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

[HKCU\Software\Microsoft\Windows\ShellNoRoam\MUICache\%Documents and Settings%\%current user%\Local Settings\Temp]
"svchost.exe" = "Microsoft® Resource File To COFF Object Conversion Utility"

The process reg.exe:2024 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "0F 8C 3B 99 5C 14 51 18 9B FD BC 6D 27 5A D5 8E"

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

The process reg.exe:1064 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "9A 7F 6E 31 C3 2D A2 80 0A CA B9 82 29 D6 3A BB"

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%\Local Settings\Temp]
"svchost.exe" = "%Documents and Settings%\%current user%\Local Settings\Temp\svchost.exe:*:Enabled:Windows Messanger"

The process reg.exe:1548 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "D5 D5 47 D7 37 6B 05 31 A4 65 31 DA 4E A7 DE 98"

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

The process reg.exe:644 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "15 50 BC 7A 4D ED 0D E5 A0 90 D4 28 8F 68 79 D3"

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]
"T70ZKG2UDZ.exe" = "%Documents and Settings%\%current user%\Application Data\T70ZKG2UDZ.exe:*:Enabled:Windows Messanger"

The process dumprep.exe:1852 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "5F 47 F6 B6 8C 11 DF D6 E9 36 5F 93 CF AD 77 F8"

The process dumprep.exe:1092 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "35 DE 5B F4 BA 20 80 B3 E0 1F 52 7A CF DC 64 08"

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:480
   rundll32.exe:132
   reg.exe:2024
   reg.exe:1064
   reg.exe:1548
   reg.exe:644
   dumprep.exe:1852
   dumprep.exe:1092

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\svchost.exe (35 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\WERde8e.dir00\svchost.exe.hdmp (211564 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\WERde8e.dir00\svchost.exe.mdmp (102001 bytes)

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

   [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
   "Windows Live" = "c:\%original file name%.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