Worm.Win32.Ainslot.VB_dc28dbcdd3

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):

FEgLT.exe:500
reg.exe:1396
reg.exe:416
reg.exe:508
reg.exe:1220
dc28dbcdd36f56d41c8d501f20543ad4.exe:1376

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

cvtres.exe:344

File activity

The process FEgLT.exe:500 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\cvtres.exe (35 bytes)

The process dc28dbcdd36f56d41c8d501f20543ad4.exe:1376 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\FEgLT.exe (289 bytes)

The process cvtres.exe:344 makes changes in a file system.

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

%Documents and Settings%\%current user%\Application Data\445E629JJN.exe (35 bytes)
%Documents and Settings%\%current user%\Application Data\BS_JDB99 (33 bytes)

Registry activity

The process FEgLT.exe:500 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "EA F1 C1 AE 6C 7C 28 C1 F9 22 9F A2 17 57 BE 11"

[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:1396 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "6B 37 84 33 FD F0 F4 05 02 AD 5B 9F F8 35 F0 26"

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]
"445E629JJN.exe" = "%Documents and Settings%\%current user%\Application Data\445E629JJN.exe:*:Enabled:Windows Messanger"

The process reg.exe:416 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "15 F0 C7 34 18 65 C7 6F 97 84 42 6A 28 36 24 57"

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

The process reg.exe:508 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "15 95 D0 1D F7 D6 CB 3F 38 E9 C3 A3 CE 5A CE DF"

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

The process reg.exe:1220 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "B3 7D E5 8A 42 C5 B9 36 8B 73 88 4B C6 C4 85 61"

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

The process dc28dbcdd36f56d41c8d501f20543ad4.exe:1376 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "CF C7 4D 9A C7 A7 20 F9 CD B1 8C 05 C4 FA 0F E2"

[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"

[HKCU\Software\Microsoft\Windows\ShellNoRoam\MUICache\%Documents and Settings%\%current user%\Local Settings\Temp]
"FEgLT.exe" = ""

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

[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"

[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 Desktop" = "%Documents and Settings%\All Users\Desktop"

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

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

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

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 urls to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"IntranetName" = "1"

The Worm modifies IE settings for security zones to map all web-nodes that bypassing proxy to the Intranet Zone:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMap]
"ProxyBypass" = "1"

The process cvtres.exe:344 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "30 DA D4 04 D3 8E D1 D0 A8 2E FD 09 E5 62 08 5D"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\run]
"Windows Firewall" = "%Documents and Settings%\%current user%\Application Data\445E629JJN.exe"

[HKLM\SOFTWARE\Microsoft\Active Setup\Installed Components\{4E72B8CB-06AB-BFDF-E05E-EDADD004BECC}]
"StubPath" = "%Documents and Settings%\%current user%\Application Data\445E629JJN.exe"

[HKCU\Software\VB and VBA Program Settings\SrvID\ID]
"CRLSBSSJ8Y" = "skymike2's Bot"

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

[HKCU\Software\Microsoft\Active Setup\Installed Components\{4E72B8CB-06AB-BFDF-E05E-EDADD004BECC}]
"StubPath" = "%Documents and Settings%\%current user%\Application Data\445E629JJN.exe"

[HKCU\Software\VB and VBA Program Settings\INSTALL\DATE]
"CRLSBSSJ8Y" = "August 22, 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 Firewall" = "%Documents and Settings%\%current user%\Application Data\445E629JJN.exe"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
"Windows Firewall" = "%Documents and Settings%\%current user%\Application Data\445E629JJN.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):

   FEgLT.exe:500
   reg.exe:1396
   reg.exe:416
   reg.exe:508
   reg.exe:1220
   dc28dbcdd36f56d41c8d501f20543ad4.exe:1376
   

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\cvtres.exe (35 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\FEgLT.exe (289 bytes)
   %Documents and Settings%\%current user%\Application Data\445E629JJN.exe (35 bytes)
   %Documents and Settings%\%current user%\Application Data\BS_JDB99 (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 Firewall" = "%Documents and Settings%\%current user%\Application Data\445E629JJN.exe"
   
   [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
   "Windows Firewall" = "%Documents and Settings%\%current user%\Application Data\445E629JJN.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