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PE_MEWSPY.A

May 05, 2015
 Analysis by: Rommel Abraham Joven
 PLATFORM:

Windows

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

  • Threat Type: File infector

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW


This file infector arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size:

342,744 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

29 Apr 2015

Arrival Details

This file infector arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This file infector drops the following copies of itself into the affected system and executes them:

  • %Application Data%\{random folder name 1}\{random file name 1}.exe

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.)

It drops the following files:

  • %Application Data%\{random folder name 1}\{random file name 2}.{random 3 letter extension}
  • %Application Data%\{random folder name 1}\{random file name 3}
  • %Application Data%\{random folder name 1}\{random folder name 2}\{random file name 4.{random 3 letter extension}
  • %Application Data%\{random folder name 1}\{random folder name 2}\{random file name 5}.{random 3 letter extension}
  • %Application Data%\{random folder name 1}\{random folder name 2}\{random file name 6}.{random 3 letter extension}
  • %Application Data%\{random folder name 1}\{random folder name 3}\{random file name 7}.{random 3 letter extension}
  • %Application Data%\{random folder name 1}\{random folder name 3}\{random file name 8}.{random 3 letter extension}
  • %Application Data%\{random folder name 1}\{random folder name 3}\{random file name 9}.{random 3 letter extension}
  • %Application Data%\{random folder name 1}\{random folder name 3}\{random file name 10}.{random 3 letter extension}
  • %Application Data%\{random folder name 1}\{random folder name 3}\{random folder name 4}\{random file name 11}.{random 3 letter extension}
  • %Application Data%\{random folder name 1}\{random folder name 3}\{random folder name 5}\{random file name 12}.{random 3 letter extension}
  • %Application Data%\{random folder name 1}\{random folder name 3}\{random folder name 5}\{random file name 13}.{random 3 letter extension}
  • %Application Data%\{random folder name 1}\{random folder name 3}\{random folder name 5}\{random file name 14}.{random 3 letter extension}
  • %Application Data%\{random folder name 1}\{random folder name 3}\{random folder name 6}\{random file name 15}.{random 3 letter extension}
  • %Application Data%\{random folder name 1}\{random folder name 3}\{random folder name 6}\{random file name 16}.{random 3 letter extension}
  • %Application Data%\{random folder name 1}\{random folder name 3}\{random folder name 6}\{random file name 17}.{random 3 letter extension}
  • %Application Data%\{random folder name 1}\{random folder name 3}\{random folder name 6}\{random file name 18}.{random 3 letter extension}
  • %Application Data%\{random folder name 1}\{random folder name 3}\{random folder name 6}\{random file name 19}.{random 3 letter extension}
  • %Application Data%\{random folder name 1}\{random folder name 3}\{random folder name 6}\{random file name 20}.{random 3 letter extension}

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.)

It creates the following folders:

  • %Application Data%\{random folder name 1}
  • %Application Data%\{random folder name 1}\{random folder name 2}
  • %Application Data%\{random folder name 1}\{random folder name 3}
  • %Application Data%\{random folder name 1}\{random folder name 3}\{random folder name 4}
  • %Application Data%\{random folder name 1}\{random folder name 3}\{random folder name 5}
  • %Application Data%\{random folder name 1}\{random folder name 3}\{random folder name 6}

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.)

Other System Modifications

This file infector adds the following registry entries:

HKEY_USERS\{SID}_CLASSES\{random key1}\
shell\open\command
(empty) = ""%Application Data%\{random folder name 1}\{random file name 1}.exe" /START "%1" %*"

HKEY_USERS\{SID}_CLASSES\{random key1}\
shell\open\command
IsolatedCommand = ""%Application Data%\{random folder name 1}\{random file name 1}.exe" /START "%1" %*"

HKEY_USERS\{SID}_CLASSES\{random key1}\
shell\open\command
(empty) = ""%Application Data%\{random folder name 1}\{random file name 1}.exe" /RUNAS /START "%1" %*"

HKEY_USERS\{SID}_CLASSES\{random key1}\
shell\open\command
IsolatedCommand = ""%Application Data%\{random folder name 1}\{randome file name 1}.exe" /RUNAS /START "%1" %*"

HKEY_USERS\{SID}_CLASSES\{random key2}\
shell\open\command
(empty) = ""%Application Data%\{random folder name 1}\{random file name 1}.exe" /START "%1" %*"

HKEY_USERS\{SID}_CLASSES\{random key2}\
shell\open\command
IsolatedCommand = ""%Application Data%\{random folder name 1}\{random file name 1}.exe" /START "%1" %*"

HKEY_USERS\{SID}_CLASSES\{random key2}\
shell\open\command
(empty) = ""%Application Data%\{random folder name 1}\{random file name 1}.exe" /START "%1" %*"

HKEY_USERS\{SID}_CLASSES\{random key2}\
shell\open\command
IsolatedCommand = ""%Application Data%\{random folder name 1}\{random file name 1}.exe" /RUNAS /START "%1" %*"

HKEY_USERS\{SID}_CLASSES\{random key2}\
shell\open\command
(empty) = "{00021401-0000-0000-C000-000000000046}"

HKEY_USERS\{SID}_CLASSES\.lnk
(empty) = "{random key2}"

It adds the following registry keys as part of its installation routine:

HKEY_USERS\{SID}_CLASSES\{random key1}

HKEY_USERS\{SID}_CLASSES\{random key2}

Mobile Malware Routine

This file infector accesses the following possibly malicious URL(s):

  • {BLOCKED}cupmtw5b2xx.onion
  • {BLOCKED}qiurveapi.ddns.net
  • {BLOCKED}azip.com
  • {BLOCKED}ikho.ddns.net

  SOLUTION

Minimum Scan Engine:

9.750

FIRST VSAPI PATTERN FILE:

11.640.02

FIRST VSAPI PATTERN DATE:

30 Apr 2015

VSAPI OPR PATTERN File:

11.641.00

VSAPI OPR PATTERN Date:

01 May 2015

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

The following created files/folders/registry keys/registry entries cannot be identified by the user since there are no reference values in the created key. The only way it can be identified is by comparing the present system information with a backup. Note that the said components do not have to be deleted since it won't be harmful to the system.

  • HKEY_USERS\{SID}_CLASSES\{random key1}
  • HKEY_USERS\{SID}_CLASSES\{random key2}
  • %Application Data%\{random folder name1}

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_USERS\{SID}_CLASSES\.lnk
    • (empty) = "{random key2}"

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as PE_MEWSPY.A. 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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