PE_EXPIRO.MKI

February 03, 2013
 Analysis by: Jed Valderama
 ALIASES:

Virus.Win32.Expiro.w (Kaspersky); Virus:Win32/Expiro.AZ (Microsoft)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: File infector

  • Destructiveness: No

  • Encrypted: Yes

  • 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.

It infects files by overwriting code in the entry point and saving the overwritten code in the virus body. It then appends the virus body to the host file.

It connects to a website to send and receive information.

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

Varies

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

03 Aug 2012

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 files:

  • %Application Data%\wsr{two random numbers}zt{two random numbers}.dll

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • kkq-vx-mtx{number}
  • gazavat-svc

File Infection

This file infector infects files by overwriting code in the entry point and saving the overwritten code in the virus body. It then appends the virus body to the host file.

Backdoor Routine

This file infector connects to the following websites to send and receive information:

  • {BLOCKED}vrc-usb10bitz.com
  • {BLOCKED}o-pestarz.ru
  • {BLOCKED}ational-spcsz.ru
  • {BLOCKED}axxlubz.ru
  • {BLOCKED}vrc-usb10bitz.com
  • {BLOCKED}vvz.net
  • {BLOCKED}-ydyg.ru
  • {BLOCKED}bugin.com
  • {BLOCKED}bikav.com
  • {BLOCKED}boneb.com
  • {BLOCKED}-aquh.ru
  • {BLOCKED}betop.com
  • {BLOCKED}.{BLOCKED}.19.33
  • www.{BLOCKED}-locmocz.ws
  • www.{BLOCKED}ckshopsz.ru
  • {BLOCKED}ckshopsz.ru
  • {BLOCKED}ashingz.cc

Download Routine

As of this writing, the said sites are inaccessible.

NOTES:

This malware may also arrive as an infected file.

  SOLUTION

Minimum Scan Engine:

8.900

FIRST VSAPI PATTERN FILE:

9.301.00

FIRST VSAPI PATTERN DATE:

03 Aug 2012

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

Search and delete this file

[ Learn More ]

There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files and folders in the search result.
  • %Application Data%\wsr{two random numbers}zt{two random numbers}.dll

Step 3

Scan your computer with your Trend Micro product to clean files detected as PE_EXPIRO.MKI. 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.

Step 4

Scan your computer with your Trend Micro product to delete files detected as PE_EXPIRO.MKI. 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.

Step 5

Search and delete this file

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result. DATA_GENERIC
  • In the Look In drop-down list, select My Computer then press Enter.
  • Once located, select the file then press SHIFT+DELETE to delete it.

    • • For Windows Vista and Windows 7 users:

    1. Click Start>Computer.
    2. In the Search input box, type the following:
      DATA_GENERIC
    3. Once located, select the file then press SHIFT+DELETE to delete it.
      *Note: Read the following Microsoft page if these steps do not work on Windows 7.


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