Modified by: Arvin Roi Macaraeg
ALIASES:

Trojan:Win32/Tiggre!rfn(Microsoft); HEUR:Exploit.RTF.CVE-2017-11882.gen(Kaspersky); RTF/CVE_2017_11882.4FB0!exploit(Fortinet)

 PLATFORM:

Windows

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

  • Threat Type: Exploit

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

This Exploit arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It takes advantage of software vulnerabilities to allow a remote user or malware/grayware to download files.

However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 478,683 bytes
File Type: DOC
Memory Resident: No
Initial Samples Received Date: 17 Oct 2019
Payload: Connects to URLs/IPs, Downloads files, Exploits vulnerability

Arrival Details

This Exploit arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

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

Download Routine

This Exploit accesses the following websites to download files:

  • http://{BLOCKED}.{BLOCKED}.38.15:1010/hta
  • http://{BLOCKED}.{BLOCKED}.38.15:1010/get

It takes advantage of the following software vulnerabilities to allow a remote user or malware/grayware to download files:

It saves the files it downloads using the following names:

  • %Public%\kbg.exe

(Note: %Public% is the folder that serves as a repository of files or folders common to all users, which is usually C:\Users\Public in Windows Vista, 7, and 8.)

Other Details

However, as of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 15.436.08
FIRST VSAPI PATTERN DATE: 17 Oct 2019
VSAPI OPR PATTERN File: 15.437.00
VSAPI OPR PATTERN Date: 18 Oct 2019

Step 1

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 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

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.
  • %Public%\kbg.exe

Step 4

Scan your computer with your Trend Micro product to delete files detected as Trojan.W97M.CVE201711882.PVSGW. 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 the following Trend Micro Support pages for more information:

Step 5

Download and apply these security patches Refrain from using these products until the appropriate patches have been installed. Trend Micro advises users to download critical patches upon release by vendors. CVE-2017-11882 | Microsoft Office Memory Corruption Vulnerability


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