Backdoor.Win32.Farfli_5ab7472e21

Dynamic Analysis

Payload

Behaviour	Description
WormAutorun	A worm can spread via removable drives. It writes its executable and creates "autorun.inf" scripts on all removable drives. The autorun script will execute the Backdoor's file once a user opens a drive's folder in Windows Explorer.

Process activity

The Backdoor creates the following process(es):

%original file name%.exe:2356
WindowsMonitor.exe:556

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

WindowsMonitor.exe:3560
svchost.exe:3348

File activity

The process %original file name%.exe:2356 makes changes in the file system.

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

%Program Files%\WindowsMonitorConfig\WindowsMonitor.exe (601 bytes)

The Backdoor deletes the following file(s):

%Program Files%\WindowsMonitorConfig\__tmp_rar_sfx_access_check_928500 (0 bytes)

The process WindowsMonitor.exe:3560 makes changes in the file system.

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

%Documents and Settings%\%current user%\Application Data\Microsoft\Windows\44f874e8t78r7t8r7e8454h564gh564gf86h48gf.dat (314 bytes)
%System%\ConfigSystem\WindowsMonitor.exe (601 bytes)
%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\desktop.ini (67 bytes)

The Backdoor deletes the following file(s):

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

Registry activity

The process %original file name%.exe:2356 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "5B 15 76 B3 47 FF 4A 8C C4 30 22 2F F3 91 43 D8"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{fdd9f6f3-7454-11e2-b4cd-806d6172696f}]
"BaseClass" = "Drive"

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

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

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

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{773a730e-74fb-11e2-b597-000c293bdf2f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\ShellNoRoam\MUICache\%Program Files%\WindowsMonitorConfig]
"WindowsMonitor.exe" = "WindowsMonitor"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{fdd9f6f2-7454-11e2-b4cd-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{fdd9f6f5-7454-11e2-b4cd-806d6172696f}]
"BaseClass" = "Drive"

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

[HKCU\Software\WinRAR SFX]
"C%%Program Files%WindowsMonitorConfig" = "%Program Files%\WindowsMonitorConfig"

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

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

The Backdoor modifies IE settings for security zones to map all web-nodes that bypassing the 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 urls to the Intranet Zone:

"IntranetName" = "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 process WindowsMonitor.exe:3560 makes changes in the system registry.

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

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{fdd9f6f3-7454-11e2-b4cd-806d6172696f}]
"BaseClass" = "Drive"

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

[HKLM\SOFTWARE\Microsoft\Active Setup\Installed Components\sdgfg4984r8997ey87t98y79789684sdgsgfpoiqpoioriertretrektokknn]
"StubPath" = "%System%\ConfigSystem\WindowsMonitor.exe restart"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\Connections]
"SavedLegacySettings" = "46 00 00 00 41 00 00 00 01 00 00 00 00 00 00 00"

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

[HKCU\Software\XtremeRAT]
"Mutex" = "44f874e8t78r7t8r7e8454h564gh564gf86h48gf"

[HKCU\Software\44f874e8t78r7t8r7e8454h564gh564gf86h48gf]
"ServerName" = "%System%\ConfigSystem\WindowsMonitor.exe"

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

[HKLM\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication]
"ID" = "1400271546"

[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\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication]
"Name" = "WindowsMonitor.exe"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{fdd9f6f2-7454-11e2-b4cd-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\44f874e8t78r7t8r7e8454h564gh564gf86h48gf]
"LastSize" = "0"

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "D1 FF 2A 68 D9 1D 4C F9 1E 45 09 EF 72 A4 AD 24"

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

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{773a730e-74fb-11e2-b597-000c293bdf2f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{fdd9f6f5-7454-11e2-b4cd-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\44f874e8t78r7t8r7e8454h564gh564gf86h48gf]
"ServerStarted" = "01/06/2014 01:56:22"

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"

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"

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]
"WindowsMonitor.exe" = "%System%\ConfigSystem\WindowsMonitor.exe"

[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
"WindowsMonitor.exe" = "%System%\ConfigSystem\WindowsMonitor.exe"

The Backdoor modifies IE settings for security zones to map all web-nodes that bypassing the proxy to the Intranet Zone:

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

The Backdoor deletes the following value(s) in system registry:

[HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings]
"AutoConfigURL"
"ProxyServer"
"ProxyOverride"

The process WindowsMonitor.exe:556 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "25 58 60 1B DB 39 E4 8F 4E A3 37 CA BD 5F B8 E2"

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]
"Windows Monitor" = "%Program Files%\WindowsMonitorConfig\WindowsMonitor.exe"

Dropped PE files

MD5	File path
f28aa886444e212469165e88698069d3	c:\Program Files\WindowsMonitorConfig\WindowsMonitor.exe
f28aa886444e212469165e88698069d3	c:\WINDOWS\system32\ConfigSystem\WindowsMonitor.exe

HOSTS file anomalies

No changes have been detected.

Rootkit activity

No anomalies have been detected.

Propagation

A worm can spread via removable drives. It writes its executable and creates "autorun.inf" scripts on all removable drives. The autorun script will execute the Backdoor's file once a user opens a drive's folder in Windows Explorer.

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:2356
   WindowsMonitor.exe:556
   

2. Delete the original Backdoor file.
   
3. Delete or disinfect the following files created/modified by the Backdoor:

   %Program Files%\WindowsMonitorConfig\WindowsMonitor.exe (601 bytes)
   %Documents and Settings%\%current user%\Application Data\Microsoft\Windows\44f874e8t78r7t8r7e8454h564gh564gf86h48gf.dat (314 bytes)
   %System%\ConfigSystem\WindowsMonitor.exe (601 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):

   [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
   "WindowsMonitor.exe" = "%System%\ConfigSystem\WindowsMonitor.exe"
   
   [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
   "WindowsMonitor.exe" = "%System%\ConfigSystem\WindowsMonitor.exe"
   
   [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
   "Windows Monitor" = "%Program Files%\WindowsMonitorConfig\WindowsMonitor.exe"

5. Find and delete all copies of the worm's file together with "autorun.inf" scripts on removable drives.
   
6. Reboot the computer.
   

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

Static Analysis

VersionInfo

No information is available.

No information is available.

PE Sections

Name	Virtual Address	Virtual Size	Raw Size	Entropy	Section MD5
.text	4096	51553	51712	4.52918	6e1bc625cba081cd77d936dde461f0fe
.rdata	57344	7029	7168	3.44765	1f979c8b2c924276d339a2610fc742b5
.data	65536	121304	512	0.89898	2e0a815532c7fa1bc90cc6f513ae2b95
.CRT	188416	16	512	0.147711	f020b6536e0e65bd519bc2f3f112cd03
.rsrc	192512	104828	104960	5.21191	d2fab1e363aab9181bcaffca5c9d0459

Dropped from:

Downloaded by:

Similar by SSDeep:

Similar by Lavasoft Polymorphic Checker:

Network Activity

URLs

IDS verdicts (Suricata alerts: Emerging Threats ET ruleset)

Traffic

Map

The Backdoor connects to the servers at the folowing location(s):

Strings from Dumps

WindowsMonitor.exe_3560:

`.rsrc

`.rsrc

ServerKeyloggerU

ServerKeyloggerU