Worm.Win32.Ainslot.VB_2c2aab3fc7

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:1856
reg.exe:1652
reg.exe:1284
reg.exe:592
reg.exe:184
reg.exe:580

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

cvtres.exe:372

File activity

The process %original file name%.exe:1856 makes changes in the file system.

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

%Documents and Settings%\%current user%\Application Data\hJQMZ3mL\local.exe.lnk (861 bytes)
%Documents and Settings%\%current user%\Application Data\hJQMZ3mL\5po8p0eUxzTbg9ch5r (48148 bytes)

The process cvtres.exe:372 makes changes in the file system.

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

%Documents and Settings%\%current user%\Application Data\csrv.exe (32 bytes)
%Documents and Settings%\%current user%\Application Data\TQA3VNORDO.exe (35 bytes)

Registry activity

The process %original file name%.exe:1856 makes changes in the system registry.

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

[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 Start Menu" = "%Documents and Settings%\All Users\Start Menu"

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

[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 AppData" = "%Documents and Settings%\All Users\Application Data"

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

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

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

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

[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"

"CommonMusic" = "%Documents and Settings%\All Users\Documents\My Music"

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

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "BA 61 44 64 92 5C 32 59 1F A3 C8 F0 18 72 CA 75"

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

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 web-nodes that bypassing proxy to the Intranet Zone:

"ProxyBypass" = "1"

The Worm modifies IE settings for security zones to map all urls to the Intranet Zone:

"IntranetName" = "1"

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" = "06 7A B6 B6 DD 02 E8 AD E8 16 2C 4E 89 C3 28 8D"

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

The process reg.exe:1284 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 0F 2C EA DC AE AD 5D 56 15 11 F0 54 ED 73 0B"

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

The process reg.exe:592 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "DC 84 78 83 7E 6E 74 2A 50 FB 94 D1 E7 D3 5E 51"

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]
"TQA3VNORDO.exe" = "%Documents and Settings%\%current user%\Application Data\TQA3VNORDO.exe:*:Enabled:Windows Messanger"

The process reg.exe:184 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "E8 0C B2 01 7D E3 94 08 12 C8 56 1E 8C 3A 7E 47"

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]
"cvtres.exe" = "%WinDir%\Microsoft.NET\Framework\v2.0.50727\cvtres.exe:*:Enabled:Windows Messanger"

The process reg.exe:580 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "1F 12 4B 98 B2 40 D3 04 75 96 39 77 24 04 BE 2B"

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]
"csrv.exe" = "%Documents and Settings%\%current user%\Application Data\hJQMZ3mL\local.exe.lnk"

The process cvtres.exe:372 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "87 7E 21 56 24 AD 18 59 A1 FF 17 F2 08 47 E9 34"

[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]
"IZ6MDTTHGR" = "Local"

[HKCU\Software\VB and VBA Program Settings\INSTALL\DATE]
"IZ6MDTTHGR" = "January 8, 2014"

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:1856
   reg.exe:1652
   reg.exe:1284
   reg.exe:592
   reg.exe:184
   reg.exe:580
   

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\hJQMZ3mL\local.exe.lnk (861 bytes)
   %Documents and Settings%\%current user%\Application Data\hJQMZ3mL\5po8p0eUxzTbg9ch5r (48148 bytes)
   %Documents and Settings%\%current user%\Application Data\csrv.exe (32 bytes)
   %Documents and Settings%\%current user%\Application Data\TQA3VNORDO.exe (35 bytes)

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

   [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
   "csrv.exe" = "%Documents and Settings%\%current user%\Application Data\hJQMZ3mL\local.exe.lnk"

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