Backdoor.Win32.Kelihos_97f64c7ad2

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):

97f64c7ad29544f4a1c1fcedc93e4bbb.exe:1656

File activity

The process 97f64c7ad29544f4a1c1fcedc93e4bbb.exe:1656 makes changes in a 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\OPQNSD2J\calc[1].exe (812 bytes)

The Backdoor deletes the following file(s):

C:\tmp.exe (0 bytes)

Registry activity

The process 97f64c7ad29544f4a1c1fcedc93e4bbb.exe:1656 makes changes in a 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"

[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"

[HKCU\Software\Microsoft\Notepad]
"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" = "D5 80 F9 7F 7A F9 06 2F F1 30 85 9D DD EC 0D 9F"

[HKCU\Software\Sysinternals\Process Monitor]
"DefaultCompressedRecord" = "D5 80 F9 7F 73 07 55 0E 49 B0 E7 20 42 AE 35 EF"

[HKCU\Software\Microsoft\Notepad]
"sizeCompletedValid" = "DDLkdEu7CFF8AroOHjBLsDKeXNUBdnNv kzKmxs gkUU56 NcA6SLbtHag0OaKKpRQ=="

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

[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 61 00 02 01 10"

[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"

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

[HKCU\Software\Sysinternals\Process Monitor]
"RecordModifiedMax" = "DDLkdEu7CFF8AroOHjBLsDKeXNUBdnNv kzKmxs gkUU56 NcA6SLbtHag0OaKKpRQ=="

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

[HKLM\System\CurrentControlSet\Services\nm\Parameters]
"ComputerName" = "XP6"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Connections]
"SavedLegacySettings" = "3C 00 00 00 14 00 00 00 01 00 00 00 00 00 00 00"

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

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

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

[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\Cryptography\RNG]
"Seed" = "A2 27 99 79 83 FE 10 83 ED 86 0B 0D 90 F7 AE 88"

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

[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"

[HKCU\Software\Microsoft\Notepad]
"activeModifiedTheme" = "D5 80 F9 7F 87 51 B7 98 B3 6C 73 59 83 EF 6A 5E"

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

[HKCU\Software\Microsoft\Internet Explorer\Main]
"LineLoadedQuick" = "DDLkdEu7CFF8AroOHjBLsDKeXNUBdnNv kzKmxs gkUU56 NcA6SLbtHag0OaKKpRQ=="

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:

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

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"

Proxy settings are disabled:

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

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]
"NetworkVerifyer" = "c:\97f64c7ad29544f4a1c1fcedc93e4bbb.exe"

The Backdoor 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 Backdoor 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"

Network activity (URLs)

URL	IP
hxxp://37.194.140.7/login.htm
hxxp://37.194.140.7/index.htm
hxxp://c5opkre.jirinec.org/calc.exe (Malicious)

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\Temporary Internet Files\Content.IE5\OPQNSD2J\calc[1].exe (812 bytes)

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

   [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
   "NetworkVerifyer" = "c:\97f64c7ad29544f4a1c1fcedc93e4bbb.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