Analysis by: John Anthony Banes

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware

This Backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites. It may be downloaded by other malware/grayware/spyware from remote sites.

It executes commands from a remote malicious user, effectively compromising the affected system.

It modifies the Internet Explorer Zone Settings.

  TECHNICAL DETAILS

File Size: 256,512 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 24 Aug 2017
Payload: Connects to URLs/IPs, Downloads files, Compromises system security, Steals information

Arrival Details

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

It may be downloaded by other malware/grayware/spyware from remote sites.

Installation

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

  • d4fy3ykdk2ddssr

Backdoor Routine

This Backdoor executes the following commands from a remote malicious user:

  • Reports gathered information:
    • System Language
    • Computer Name
    • OS Version
    • Host Name
    • Arbitrary List of Files
    • Available Drives and their types
  • Create/Terminate Arbitrary Processes
  • Create/Delete Arbitrary Files
  • Download/Upload arbitrary files from/to the C&C server
  • Allocate console to process using console name: dkkwldngn
  • Terminate Self

It connects to the following URL(s) to send and receive commands from a remote malicious user:

  • http://{BLOCKED}i.com/danbata/hinsyu/kiyomi/Thunds.php?{random string}={hardcoded string 1}{hardcoded string 2}{type identifier byte: "1"=recv, "2"=send}{random string or encrypted user data}

Web Browser Home Page and Search Page Modification

This Backdoor modifies the Internet Explorer Zone Settings.

NOTES:

This backdoor has an activity time between 8:00 and 18:00.

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 13.616.04
FIRST VSAPI PATTERN DATE: 25 Aug 2017
VSAPI OPR PATTERN File: 13.617.00
VSAPI OPR PATTERN Date: 26 Aug 2017

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

Identify and terminate files detected as BKDR64_DATPER.B

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 3

Scan your computer with your Trend Micro product to delete files detected as BKDR64_DATPER.B. 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

Reset Internet security settings

[ Learn More ]


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