Backdoor.Win32.Kelihos_e8b737cbfc

Dynamic Analysis

Payload

No specific payload has been found.

Process activity

The Backdoor creates the following process(es):

temp2179240182.exe:3388
%original file name%.exe:2656
IEXPLORE.EXE:3448

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

temp3837552984.exe:2196

File activity

The process %original file name%.exe:2656 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\temp2179240182.exe (7972 bytes)
%Documents and Settings%\%current user%\Local Settings\Temp\temp3837552984.exe (3914 bytes)

The process temp3837552984.exe:2196 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 IEXPLORE.EXE:3448 makes changes in the file system.

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

%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\desktop.ini (67 bytes)

Registry activity

The process temp2179240182.exe:3388 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "5F 95 D0 EE 83 DB 88 32 AF 77 AF 08 26 88 79 75"

The process temp3837552984.exe:2196 makes changes in the system registry.

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

[HKCU\Software\Microsoft\Notepad]
"infoPlayedCurrent" = "00 00 00 00 00 00 00 00"
"styleModifiedPrev" = "80"

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

[HKCU\Software\Microsoft\Internet Explorer\Main]
"PersistentLocalizedName" = "24 80 F9 7F 7A 88 0F BB 8A 44 7C 45 65 6A 68 9C"

[HKCU\Software\Sysinternals\Process Monitor]
"DefaultCompressedRecord" = "24 80 F9 7F 73 70 EA 53 AC D5 26 69 36 FE BA 12"

[HKLM\SOFTWARE\Microsoft\Internet Explorer\Main]
"IE8RunOnceLastShown" = "1"

[HKCU\Software\Microsoft\Notepad]
"sizeCompletedValid" = "DEtX/zq47KK7b63OjGsXLO8yyvQCZ8myhcMbAKZyLuKtzZL/QDfph7cdp8JZRplC1Q=="

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

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

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

[HKCU\Software\Microsoft\Internet Explorer\Main]
"DBSavedUse" = "A2 49 4D F3 D9 1E 9F 88 01 01 08 6A 00 03 19 03"

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

[HKCU\Software\Sysinternals\Process Monitor]
"FlagsModifiedValid" = "00 00 00 00 00 00 00 00"
"RecordModifiedMax" = "DEtX/zq47KK7b63OjGsXLO8yyvQCZ8myhcMbAKZyLuKtzZL/QDfph7cdp8JZRplC1Q=="

[HKLM\SOFTWARE\Microsoft\Internet Explorer\Main]
"IE8TourShown" = "1"

[HKLM\System\CurrentControlSet\Services\nm\Parameters]
"ComputerName" = "XP2"

[HKLM\SOFTWARE\Microsoft\Internet Explorer\Main]
"IE8RunOncePerInstallCompleted" = "1"

[HKCU\Software\Microsoft\Internet Explorer\Main]
"NoProtectedModeBanner" = "1"

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

[HKCU\Software\Microsoft\Internet Explorer\Main]
"IE8RunOncePerInstallCompleted" = "1"

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "6D 75 59 A9 84 1E 46 EA 24 7B E7 65 65 95 93 47"

[HKCU\Software\Microsoft\Internet Explorer\Main]
"PlatformCompressedValid" = "00 00 00 00 00 00 00 00"

[HKLM\SOFTWARE\Microsoft\Internet Explorer\Main]
"NoProtectedModeBanner" = "1"
"Check_Associations" = "no"

[HKCU\Software\Microsoft\Notepad]
"activeModifiedTheme" = "24 80 F9 7F 87 D3 26 26 98 8A 29 59 DD 4F BF EF"

[HKCU\Software\Microsoft\Internet Explorer\Main]
"RecordEnabledCheck" = "80"
"LineLoadedQuick" = "DEtX/zq47KK7b63OjGsXLO8yyvQCZ8myhcMbAKZyLuKtzZL/QDfph7cdp8JZRplC1Q=="

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\temp3837552984.exe"

The process IEXPLORE.EXE:3448 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "A5 09 9B 14 8D C9 22 27 2B 09 4C 4E E3 B8 DC 2E"

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

[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"
"Favorites" = "%Documents and Settings%\%current user%\Favorites"

[HKCU\Software\Microsoft\Internet Explorer\Main]
"CompatibilityFlags" = "0"

Network activity (URLs)

URL	IP
hxxp://195.42.127.249/mod1/yanicha.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):

   temp2179240182.exe:3388
   %original file name%.exe:2656
   IEXPLORE.EXE:3448

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\temp2179240182.exe (7972 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temp\temp3837552984.exe (3914 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\desktop.ini (67 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\temp3837552984.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