Backdoor.Win32.Fynloski_bdec5a60da

Dynamic Analysis

Payload

No specific payload has been found.

Process activity

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

keygen.exe:820
WinUpdate.exe:1548
%original file name%.exe:1120

File activity

The process %original file name%.exe:1120 makes changes in the file system.

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

%Documents and Settings%\%current user%\Local Settings\Temp\Win Update\Win Update.exe (5441 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\keygen.exe (16 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\AppLunch\Cho.ine (7547 bytes)

Registry activity

The process keygen.exe:820 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "8A F4 DE 2B 9B CB 97 9E CF EF 99 C6 FB C9 08 B3"

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

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "C7 28 15 2D 98 80 29 C8 AE 95 57 6A F7 BB 67 66"

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

[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"

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

The process %original file name%.exe:1120 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "86 7A C0 85 17 AD 25 29 D7 56 BB 5F BB 21 71 57"

[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]
"keygen.exe" = "keygen"

[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"

[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"

The Backdoor 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 Backdoor 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:

"UNCAsIntranet" = "1"

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

"IntranetName" = "1"

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

[HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
"Win Update" = "%Documents and Settings%\%current user%\Local Settings\Temp\Win Update\Win Update.exe"

Network activity (URLs)

URL	IP
plurnt.bounceme.net	193.0.200.185

HOSTS file anomalies

No changes have been detected.

Rootkit activity

No anomalies have been detected.

Propagation

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 the original Backdoor's process (How to End a Process With the Task Manager).
2. Delete the original Backdoor file.
   
3. Delete or disinfect the following files created/modified by the Backdoor:

   %Documents and Settings%\%current user%\Local Settings\Temp\Win Update\Win Update.exe (5441 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\keygen.exe (16 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\AppLunch\Cho.ine (7547 bytes)

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

   [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
   "Win Update" = "%Documents and Settings%\%current user%\Local Settings\Temp\Win Update\Win Update.exe"

5. Clean the Temporary Internet Files folder, which may contain infected files (How to clean Temporary Internet Files folder).
   
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