Backdoor.Win32.Farfli_eb383a0ef3

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:356
%original file name%.exe:336

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

calc.exe:168
svchost.exe:500

Mutexes

The following mutexes were created/opened:No objects were found.

File activity

The process calc.exe:168 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)
%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\D5UZC56B\desktop.ini (67 bytes)
%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\IJORGDMN\desktop.ini (67 bytes)
%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\WDMNSTY3\desktop.ini (67 bytes)
%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\WFAXAP63\desktop.ini (67 bytes)
%Documents and Settings%\%current user%\Application Data\Microsoft\Windows\Ql76dPCT5zbE.dat (322 bytes)
%WinDir%\InstallDir\شادو حزين.exe (2321 bytes)

Registry activity

The process calc.exe:168 makes changes in the 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"
"CachePath" = "%Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\Cache4"

[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"

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

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

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

[HKLM\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication]
"ID" = "998081552"

[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\MountPoints2\{c155cd75-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKLM\SOFTWARE\Microsoft\Active Setup\Installed Components\{A4GEFBB2-ANQR-TV0C-RQ56-3C565U5EKB3A}]
"StubPath" = "%WinDir%\InstallDir\شادو حزين.exe restart"

[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" = "calc.exe"

[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\Ql76dPCT5zbE]
"ServerName" = "%WinDir%\InstallDir\شادو حزين.exe"

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "24 19 F8 6E A4 37 69 32 A8 14 34 C6 03 D5 22 4C"

[HKCU\Software\Ql76dPCT5zbE]
"ServerStarted" = "05/07/2014 05:39:10"

[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\MountPoints2\{c155cd72-744b-11e2-8294-806d6172696f}]
"BaseClass" = "Drive"

[HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2\{b98117e8-75ca-11e2-81b2-000c293708fb}]
"BaseClass" = "Drive"

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

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"

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]
"HKLM" = "%WinDir%\InstallDir\شادو حزين.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 modifies IE settings for security zones to map all web-nodes that bypassing the proxy to the Intranet Zone:

"ProxyBypass" = "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]
"HKCU" = "%WinDir%\InstallDir\شادو حزين.exe"

Proxy settings are disabled:

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

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

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

The process %original file name%.exe:356 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "C0 F4 33 C7 3E 52 8E 73 DE 4C CD E2 5A 6E 59 EC"

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

[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\XtremeRAT]
"Mutex" = "Ql76dPCT5zbE"

The process %original file name%.exe:336 makes changes in the system registry.

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

[HKLM\SOFTWARE\Microsoft\Cryptography\RNG]
"Seed" = "45 9A A5 A9 A3 E4 46 1F 74 0C C9 A1 EF 2D B3 2D"

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

Dropped PE files

There are no dropped PE files.

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:356
   %original file name%.exe:336
   

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\desktop.ini (67 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\D5UZC56B\desktop.ini (67 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\IJORGDMN\desktop.ini (67 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\WDMNSTY3\desktop.ini (67 bytes)
   %Documents and Settings%\%current user%\Local Settings\Temporary Internet Files\Content.IE5\WFAXAP63\desktop.ini (67 bytes)
   %Documents and Settings%\%current user%\Application Data\Microsoft\Windows\Ql76dPCT5zbE.dat (322 bytes)
   %WinDir%\InstallDir\شادو حزين.exe (2321 bytes)

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

   [HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run]
   "HKLM" = "%WinDir%\InstallDir\شادو حزين.exe"
   
   [HKCU\Software\Microsoft\Windows\CurrentVersion\Run]
   "HKCU" = "%WinDir%\InstallDir\شادو حزين.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

Company Name: Nr1tkNMTNmVUs
Product Name: Vu!xmUU2Up53v
Product Version: 4.1.5.?0
Legal Copyright: Nr1tkNMTNmVUs
Legal Trademarks: Vu!xmUU2Up53v
Original Filename: 4545.exe
Internal Name: 4545.exe
File Version: 4.1.5.?0
File Description: Nr1tkNMTNmVUs
Comments: Vu!xmUU2Up53v
Language: English (United States)

Company Name: Nr1tkNMTNmVUsProduct Name: Vu!xmUU2Up53vProduct Version: 4.1.5.?0Legal Copyright: Nr1tkNMTNmVUsLegal Trademarks: Vu!xmUU2Up53vOriginal Filename: 4545.exeInternal Name: 4545.exeFile Version: 4.1.5.?0File Description: Nr1tkNMTNmVUsComments: Vu!xmUU2Up53vLanguage: English (United States)

PE Sections

Name	Virtual Address	Virtual Size	Raw Size	Entropy	Section MD5
.rsrc	8192	960	1024	2.17334	9f0efe3e19fec38b716e27b88322abf7
.text	16384	397880	398336	5.38201	92eca491a960c698eb21fbfc395da612
.reloc	417792	12	512	0.084755	4e91ab48f5d75251872b8ee636bb001e

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

svchost.exe_500:

.text

.text

`.data

`.data

.rsrc

.rsrc

ADVAPI32.dll

ADVAPI32.dll

KERNEL32.dll

KERNEL32.dll

NTDLL.DLL

NTDLL.DLL

RPCRT4.dll

RPCRT4.dll

NETAPI32.dll

NETAPI32.dll

ole32.dll

ole32.dll

ntdll.dll

ntdll.dll

RegCloseKey

RegCloseKey

RegOpenKeyExW

RegOpenKeyExW

GetProcessHeap

GetProcessHeap

NtOpenKey

NtOpenKey

svchost.pdb

svchost.pdb

\PIPE\

\PIPE\

Software\Microsoft\Windows NT\CurrentVersion\Svchost

Software\Microsoft\Windows NT\CurrentVersion\Svchost

\Registry\Machine\System\CurrentControlSet\Control\SecurePipeServers\

\Registry\Machine\System\CurrentControlSet\Control\SecurePipeServers\

5.1.2600.5512 (xpsp.080413-2111)

5.1.2600.5512 (xpsp.080413-2111)

svchost.exe

svchost.exe

Windows

Windows

Operating System

Operating System

5.1.2600.5512

5.1.2600.5512

svchost.exe_500_rwx_10000000_0004A000:

.idata

.idata

.rdata

.rdata

P.reloc

P.reloc

P.rsrc

P.rsrc

ServerKeyloggerU

ServerKeyloggerU