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BKDR_ANDROM.YYSLA

July 08, 2016
 Analysis by: Mar Philip Elaurza
 ALIASES:

Troj/Androm-JF (Sophos); Worm:Win32/Gamarue (Microsoft)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW


This backdoor modifies the Internet Explorer Zone Settings.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

210,432 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

05 Jul 2016

Installation

This backdoor drops the following copies of itself into the affected system:

  • %All Users Profile%\ms{random}.exe

(Note: %All Users Profile% is the All Users folder, where it usually is C:\Documents and Settings\All Users on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\ProgramData on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Autostart Technique

This backdoor adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
{random numbers} = "%All Users Profile%\ms{random}.exe"

Other System Modifications

This backdoor adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
TaskbarNoNotification = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer
TaskbarNoNotification = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
HideSCAHealth = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer
HideSCAHealth = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
EnableLUA = "0"

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "2"

(Note: The default value data of the said registry entry is "1".)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = "0"

(Note: The default value data of the said registry entry is "1".)

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
cval = "0"

(Note: The default value data of the said registry entry is "1".)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\MpsSvc
Start = "4"

(Note: The default value data of the said registry entry is "2".)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\SharedAccess
Start = "4"

(Note: The default value data of the said registry entry is "2".)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
services\WinDefend
Start = "4"

(Note: The default value data of the said registry entry is "2".)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\wscsvc
Start = "4"

(Note: The default value data of the said registry entry is "2".)

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\wuauserv
Start = "4"

(Note: The default value data of the said registry entry is "2".)

Web Browser Home Page and Search Page Modification

This backdoor modifies the Internet Explorer Zone Settings.

Other Details

This backdoor connects to the following URL(s) to check for an Internet connection:

  • yahoo.com
  • google.com
  • bing.com
  • update.microsoft.com
  • microsoft.com

It connects to the following possibly malicious URL:

  • {BLOCKED}.{BLOCKED}.72.26
  • {BLOCKED}.{BLOCKED}.72.27
  • {BLOCKED}.{BLOCKED}.12.116
  • {BLOCKED}.{BLOCKED}.12.249
  • {BLOCKED}.{BLOCKED}.69.79
  • {BLOCKED}.{BLOCKED}.211.150
  • {BLOCKED}.{BLOCKED}.192.45
  • {BLOCKED}.{BLOCKED}.192.46
  • {BLOCKED}.{BLOCKED}.187.26
  • {BLOCKED}.{BLOCKED}.187.27
  • {BLOCKED}.{BLOCKED}.33.119
  • {BLOCKED}.{BLOCKED}.37.72
  • {BLOCKED}.{BLOCKED}.92.168
  • {BLOCKED}.{BLOCKED}.92.184
  • {BLOCKED}.{BLOCKED}.118.240
  • {BLOCKED}.{BLOCKED}.118.35
  • {BLOCKED}.{BLOCKED}.118.36
  • {BLOCKED}.{BLOCKED}.118.37
  • {BLOCKED}.{BLOCKED}.136.26
  • {BLOCKED}.{BLOCKED}.136.27
  • {BLOCKED}.{BLOCKED}.25.26
  • {BLOCKED}.{BLOCKED}.25.27
  • {BLOCKED}.{BLOCKED}.68.26
  • {BLOCKED}.{BLOCKED}.68.27
  • {BLOCKED}.{BLOCKED}.216.25
  • {BLOCKED}.{BLOCKED}.216.26
  • {BLOCKED}.{BLOCKED}.217.202
  • {BLOCKED}.{BLOCKED}.217.203
  • {BLOCKED}.{BLOCKED}.112.32
  • {BLOCKED}.{BLOCKED}.112.33
  • {BLOCKED}.{BLOCKED}.112.34
  • {BLOCKED}.{BLOCKED}.112.37
  • {BLOCKED}.{BLOCKED}.112.38
  • http://{BLOCKED}.{BLOCKED}.32.27/121ccccccccccccccccccc222222222222222c.exe
  • http://{BLOCKED}.{BLOCKED}.32.27/123ccccccccccccccccccc222222222222222c.exe
  • http://{BLOCKED}.{BLOCKED}.32.27/133ccccccccccccccccccc222222222222222c.exe
  • http://{BLOCKED}.{BLOCKED}.32.27/136ccccccccccccccccccc222222222222222c.exe
  • http://{BLOCKED}.{BLOCKED}.32.27/17ccccccccccccccccccc222222222222222c.exe
  • http://{BLOCKED}.{BLOCKED}.32.27/193ccccccccccccccccccc222222222222222c.exe
  • http://{BLOCKED}.{BLOCKED}.32.27/226ccccccccccccccccccc222222222222222c.exe
  • http://{BLOCKED}.{BLOCKED}.32.27/74ccccccccccccccccccc222222222222222c.exe
  • http://{BLOCKED}.{BLOCKED}.32.27/82ccccccccccccccccccc222222222222222c.exe
  • http://{BLOCKED}.{BLOCKED}.32.27/85ccccccccccccccccccc222222222222222c.exe
  • http://{BLOCKED}.{BLOCKED}.32.27/and50a859.exe
  • http://{BLOCKED}.{BLOCKED}.32.27/nut50a859.exe
  • http://and19.{BLOCKED}orldnancy1.com/bla19/gate.php
  • http://domand.{BLOCKED}opps.com/domand/gate.php
  • http://ip.{BLOCKED}y.mobi/internals/api/ip?_=1464221956_1204
  • http://ip.{BLOCKED}y.mobi/internals/api/ip?_=1464222100_8962
  • http://ip2.{BLOCKED}y.mobi/internals/api/ip?_=1464221993_2124
  • http://ip2.{BLOCKED}y.mobi/internals/api/ip?_=1464222127_8449
  • http://ip3.{BLOCKED}y.mobi/internals/api/ip?_=1464222028_6769
  • http://ip4.{BLOCKED}y.mobi/internals/api/ip?_=1464222064_885
  • http://ip5.{BLOCKED}y.mobi/internals/api/ip?_=1464222081_495
  • http://{BLOCKED}plz.com/ip/header?id_ip=2768885359&id_provider=18
  • http://{BLOCKED}plz.com/ip/header?id_ip=2768896391&id_provider=18
  • http://{BLOCKED}plz.com/ip/header?id_ip=86444&id_provider=3
  • http://{BLOCKED}nomiranda1.com/path/tasks.php

It deletes itself after execution.

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

12.548.07

FIRST VSAPI PATTERN DATE:

25 May 2016

VSAPI OPR PATTERN File:

12.549.00

VSAPI OPR PATTERN Date:

26 May 2016

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\Explorer\Run
    • {random numbers} = "%All Users Profile%\ms{random}.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
    • TaskbarNoNotification = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer
    • TaskbarNoNotification = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
    • HideSCAHealth = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer
    • HideSCAHealth = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
    • EnableLUA = "0"

Step 5

Restore this modified registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: Hidden = "2"
      To: Hidden = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: ShowSuperHidden = "0"
      To: ShowSuperHidden = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • From: cval = "0"
      To: cval = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\MpsSvc
    • From: Start = "4"
      To: Start = "2"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\SharedAccess
    • From: Start = "4"
      To: Start = "2"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\WinDefend
    • From: Start = "4"
      To: Start = "2"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\wscsvc
    • From: Start = "4"
      To: Start = "2"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\wuauserv
    • From: Start = "4"
      To: Start = "2"

Step 6

Reset Internet security settings

[ Learn More ]

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_ANDROM.YYSLA. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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