Backdoor.Win32.Kelihos_4b93e98fbc

Dynamic Analysis

Payload

No specific payload has been found.

Process activity

The Backdoor creates the following process(es):

%original file name%.exe:912

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

temp3770113238.exe:1988

File activity

The process temp3770113238.exe:1988 makes changes in the file system.

The Backdoor deletes the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temp\tmp.exe (0 bytes)

The process %original file name%.exe:912 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\temp3770113238.exe (6297 bytes)

Registry activity

The process temp3770113238.exe:1988 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "3D 1D 96 D8 F4 7F BC 64 C9 38 2A C8 5D EF 6D F5"

[HKCU\Software\Microsoft\Notepad]
"sizeCompletedValid" = "DG11zrvkNtnvVBMQ/2dMmbjXH/Rqlfw5cbaOd4xuRfdIE8GN9kZ5XDfVkRLoT9UPHA=="

[HKCU\Software\Sysinternals\Process Monitor]
"UrlEnabledUse" = "80"

[HKLM\System\CurrentControlSet\Services\nm\Parameters]
"EnableStationQueries" = "1"
"ComputerName" = "XP9"

[HKCU\Software\Microsoft\Notepad]
"infoPlayedCurrent" = "00 00 00 00 00 00 00 00"

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

[HKCU\Software\Microsoft\Internet Explorer\Main]
"DBSavedUse" = "A2 49 4D F3 D9 1E 9F 88 01 01 08 6A 00 03 69 08"

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

[HKCU\Software\Sysinternals\Process Monitor]
"FlagsModifiedValid" = "00 00 00 00 00 00 00 00"

[HKCU\Software\Microsoft\Notepad]
"styleModifiedPrev" = "80"

[HKCU\Software\Microsoft\Internet Explorer\Main]
"PlatformCompressedValid" = "00 00 00 00 00 00 00 00"
"PersistentLocalizedName" = "DA 80 F9 7F 7A BD 47 1E DE 57 74 A7 5F 70 D7 5B"

[HKCU\Software\Sysinternals\Process Monitor]
"DefaultCompressedRecord" = "DA 80 F9 7F 73 76 3E 72 33 3A 26 A6 9B 42 AF CE"

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

[HKCU\Software\Microsoft\Notepad]
"activeModifiedTheme" = "DA 80 F9 7F 87 79 48 94 57 BB C2 45 38 47 AC 2C"

[HKCU\Software\Microsoft\Internet Explorer\Main]
"RecordEnabledCheck" = "80"

[HKCU\Software\Sysinternals\Process Monitor]
"RecordModifiedMax" = "DG11zrvkNtnvVBMQ/2dMmbjXH/Rqlfw5cbaOd4xuRfdIE8GN9kZ5XDfVkRLoT9UPHA=="

[HKLM\System\CurrentControlSet\Services\nm\Parameters]
"UserName" = "%CurrentUserName%"

[HKCU\Software\Microsoft\Internet Explorer\Main]
"LineLoadedQuick" = "DG11zrvkNtnvVBMQ/2dMmbjXH/Rqlfw5cbaOd4xuRfdIE8GN9kZ5XDfVkRLoT9UPHA=="

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

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
"NetworkChecker" = "C:\DOCUME~1\"%CurrentUserName%"\LOCALS~1\Temp\temp3770113238.exe"

The process %original file name%.exe:912 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "11 3D BD D3 5E E0 C8 AC 1E 17 5A 6E FE 97 9A 83"

Network activity (URLs)

URL	IP
hxxp://46.172.68.90/traff01.exe (Malicious)

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 malicious process(es) (How to End a Process With the Task Manager):

   %original file name%.exe:912

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\temp3770113238.exe (6297 bytes)

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

   [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
   "NetworkChecker" = "C:\DOCUME~1\"%CurrentUserName%"\LOCALS~1\Temp\temp3770113238.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