Backdoor.Win32.Farfli_503384546c

by malwarelabrobot on October 14th, 2013 in Malware Descriptions.

Gen:Variant.MSILKrypt.11 (BitDefender), VirTool:MSIL/Injector.AQ (Microsoft), HEUR:Trojan.Win32.Generic (Kaspersky), Trojan.MSIL.Agent.ko (v) (VIPRE), Trojan.PWS.Spy.11887 (DrWeb), Gen:Variant.MSILKrypt.11 (B) (Emsisoft), BackDoor-FBEQ!503384546C14 (McAfee), Trojan-Dropper.MSIL (Ikarus), Gen:Variant.MSILKrypt.11 (FSecure), Dropper.Agent.10.A (AVG), MSIL:Crypt-BK [Drp] (Avast), Backdoor.Win32.Farfli.FD, Trojan.Win32.IEDummy.FD, GenericInjector.YR (Lavasoft MAS)
Behaviour: Trojan-Dropper, Trojan, Backdoor, VirTool


The description has been automatically generated by Lavasoft Malware Analysis System and it may contain incomplete or inaccurate information.

Summary
Technical Details
Removal Recommendations

MD5: 503384546c1479f025220175343c11f0
SHA1: 2a77515df81647a3951ad5e9580aa290094c5d7a
SHA256: 62b5ed1b6635b47cd20ccbd27eae860b12b05146361d6ec9760b9d3ab9f782c5
SSDeep: 1536:sNe/RqJsZHbmqsEzElt/1XmcIkCKhxDknOYif:sY5lZHqEIkcIkPg8
Size: 77824 bytes
File type: EXE
Platform: WIN32
Entropy: Not Packed
PEID: MicrosoftVisualC, NETexecutable, UPolyXv05_v6
Company: no certificate found
Created at: 2013-10-05 17:15:40


Summary:

Backdoor. Malware that enables a remote control of victim's machine.

Payload

No specific payload has been found.

Process activity

The Backdoor creates the following process(es):

503384546c1479f025220175343c11f0.exe:548
iexplore.exe:224
348.exe:1556

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

iexplore.exe:1124

File activity

The process 503384546c1479f025220175343c11f0.exe:548 makes changes in a file system.
The Backdoor creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temp\348.exe (21 bytes)

The process iexplore.exe:1124 makes changes in a file system.
The Backdoor creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Application Data\Microsoft\Windows\ast4Vt72K.dat (274 bytes)
%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\desktop.ini (67 bytes)

The process 348.exe:1556 makes changes in a file system.
The Backdoor creates and/or writes to the following file(s):

%Documents and Settings%\%current user%\Application Data\Microsoft\Windows\ast4Vt72K.cfg (2 bytes)
%WinDir%\InstallDir\Server.exe (21 bytes)

The Backdoor deletes the following file(s):

%Documents and Settings%\%current user%\Local Settings\Temp\x.html (0 bytes)

Registry activity

The process 503384546c1479f025220175343c11f0.exe:548 makes changes in a system registry.
The Backdoor creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "9F A2 61 10 D8 A0 5E E7 BD 19 BB 91 39 14 56 C2"

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

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

The process iexplore.exe:224 makes changes in a system registry.
The Backdoor creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "24 E7 73 AC 71 90 68 27 37 AB 21 93 35 A7 29 FB"

The process iexplore.exe:1124 makes changes in a system registry.
The Backdoor 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 17 00 00 00 01 00 00 00 00 00 00 00"

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "D0 14 49 12 4D B5 87 3D 30 F2 4A F8 2F 5A B6 16"

[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 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"

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"

The process 348.exe:1556 makes changes in a system registry.
The Backdoor creates and/or sets the following values in system registry:

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "8F BD A0 F2 BF 4B 68 CF D0 F1 53 ED D4 38 73 86"

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

[HKLM\SOFTWARE\Microsoft\Active Setup\Installed Components\{5460C4DF-B266-909E-CB58-E32B79832EB2}]
"StubPath" = "%WinDir%\InstallDir\Server.exe restart"

[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\ast4Vt72K]
"InstalledServer" = "%WinDir%\InstallDir\Server.exe"

[HKCU\Software\ast4Vt72K]
"ServerStarted" = "10/13/2013 2:28:46 AM"

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]
"HKCU" = "%WinDir%\InstallDir\Server.exe"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
"HKLM" = "%WinDir%\InstallDir\Server.exe"

Network activity (URLs)

No activity has been detected.

Rootkit activity

No anomalies have been detected.

Propagation


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):

    503384546c1479f025220175343c11f0.exe:548
    iexplore.exe:224
    348.exe:1556

  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\348.exe (21 bytes)
    %Documents and Settings%\%current user%\Application Data\Microsoft\Windows\ast4Vt72K.dat (274 bytes)
    %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\desktop.ini (67 bytes)
    %Documents and Settings%\%current user%\Application Data\Microsoft\Windows\ast4Vt72K.cfg (2 bytes)
    %WinDir%\InstallDir\Server.exe (21 bytes)

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

    [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
    "HKCU" = "%WinDir%\InstallDir\Server.exe"

    [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
    "HKLM" = "%WinDir%\InstallDir\Server.exe"

  5. Reboot the computer.

*Manual removal may cause unexpected system behaviour and should be performed at your own risk.