Trojan.Win32.Swrort.3_81233427a3

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 Trojan's file once a user opens a drive's folder in Windows Explorer.

Process activity

The Trojan creates the following process(es):

ddoser.exe:1384
81233427a3670b4332f4d67113f600f8.exe:1508
81233427a3670b4332f4d67113f600f8.exe:1064

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

ddoser.exe:1008

File activity

The process ddoser.exe:1008 makes changes in a file system.

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

%Documents and Settings%\%current user%\Application Data\log.err (639 bytes)

The process 81233427a3670b4332f4d67113f600f8.exe:1064 makes changes in a file system.

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

%Documents and Settings%\%current user%\Application Data\ddoser.exe (1281 bytes)

Registry activity

The process ddoser.exe:1384 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "C2 4D 9E 18 74 39 68 C0 4C E3 CC 40 E3 49 A7 57"

The process ddoser.exe:1008 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths]
"Directory" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path4]
"CacheLimit" = "65452"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path4]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache4"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path2]
"CacheLimit" = "65452"

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

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

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path2]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache2"

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

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

[HKLM\System\CurrentControlSet\Hardware Profiles\0001\Software\Microsoft\windows\CurrentVersion\Internet Settings]
"ProxyEnable" = "0"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path1]
"CacheLimit" = "65452"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Connections]
"SavedLegacySettings" = "3C 00 00 00 1B 00 00 00 01 00 00 00 00 00 00 00"

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "82 09 BD E6 0D 15 F3 52 78 54 48 DA 76 F8 50 75"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path1]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache1"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path3]
"CacheLimit" = "65452"

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

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

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths\path3]
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache3"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Internet Settings\Cache\Paths]
"Paths" = "4"

The Trojan 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 Trojan 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"

Proxy settings are disabled:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"ProxyEnable" = "0"

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

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

To automatically run itself each time Windows is booted, the Trojan adds the following link to its file to the system registry autorun key:

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

The Trojan deletes the following value(s) in system registry:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"AutoConfigURL"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"ProxyServer"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"ProxyOverride"

The process 81233427a3670b4332f4d67113f600f8.exe:1508 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "D0 4E 4C 99 51 1E 72 CC 4B 19 65 C3 A2 BF 30 6C"

The process 81233427a3670b4332f4d67113f600f8.exe:1064 makes changes in a system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "0B D8 75 41 4B 02 B1 AF 58 F2 F1 05 04 2B 61 5B"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{c155cd73-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{5c14c4f6-74da-11e2-81b0-000c29ec7fc5}]
"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 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\{c155cd75-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\ShellNoRoam\MUICache\%Documents and Settings%\%current user%\Application Data]
"ddoser.exe" = "Piriform Ltd"

[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\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 Trojan 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 Trojan 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 Trojan 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"

Network activity (URLs)

URL	IP
hxxp://178.32.27.141/run.php

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 Trojan'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):

   ddoser.exe:1384
   81233427a3670b4332f4d67113f600f8.exe:1508
   81233427a3670b4332f4d67113f600f8.exe:1064
   

2. Delete the original Trojan file.
   
3. Delete or disinfect the following files created/modified by the Trojan:

   %Documents and Settings%\%current user%\Application Data\log.err (639 bytes)
   %Documents and Settings%\%current user%\Application Data\ddoser.exe (1281 bytes)

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

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

5. Clean the Temporary Internet Files folder, which may contain infected files (How to clean Temporary Internet Files folder).
   
6. Find and delete all copies of the worm's file together with "autorun.inf" scripts on removable drives.
   
7. 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