Analysis by: Jay Garcia
ALIASES:

ALS:Downloader-B [Trj] (Avast); ALS.Kenilfe (Norton)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

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

This Trojan 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: 4,116 bytes
Memory Resident: No
Initial Samples Received Date: 11 Apr 2019
Payload: Connects to URLs/IPs, Downloads files

Arrival Details

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

  • {malware path}\shxfont.fas

Download Routine

This Trojan saves the files it downloads using the following names:

  • {directory of AutoCAD}\draw.fas

Other Details

This Trojan does the following:

  • It downloads the file from the following URL:
    • http://zxb.{BLOCKED}n.com/err/?errcode=1
  • It sets the system variable AcadLspAsDoc = 1, which tells AutoCAD to load the acad.fas file every time the operator opens another drawing.

NOTES:

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

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.943.00
FIRST VSAPI PATTERN DATE: 16 Apr 2019
VSAPI OPR PATTERN File: 14.944.00
VSAPI OPR PATTERN Date: 17 Apr 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.  
  • {malware path}\shxfont.fas
  • {directory of AutoCAD}\draw.fas

Step 4

Scan your computer with your Trend Micro product to delete files detected as Trojan.ACM.QFAS.DLDS. 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:


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