Backdoor.ASP.WEBSHELL.AX

March 14, 2019
 Analysis by: Janus Agcaoili
 ALIASES:

ASP:Rootkit-C (AVAST); Backdoor.ASP.Rootkit.10.a (KASPERSKY)

 PLATFORM:

Windows

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware, Hosted on a website

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 hosted on a website and run when a user accesses the said website.

It runs certain commands that it receives remotely from a malicious user. Doing this puts the affected computer and information found on the computer at greater risk.

  TECHNICAL DETAILS

File Size:

956 bytes

File Type:

ASP

Initial Samples Received Date:

07 Mar 2019

Payload:

Connects to URLs/IPs

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 hosted on a website and run when a user accesses the said website.

Backdoor Routine

This Backdoor executes the following command(s) from a remote malicious user:

  • Execute Arbitrary Codes

Other Details

This Backdoor does the following:

  • It receive codes from the attacker via GET command on this hosted ASP file
  • Displays the following when accessed:

It requires being hosted on a web server in order to proceed with its intended routine.

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

14.870.05

FIRST VSAPI PATTERN DATE:

14 Mar 2019

VSAPI OPR PATTERN File:

14.871.00

VSAPI OPR PATTERN Date:

15 Mar 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

Scan your computer with your Trend Micro product to delete files detected as Backdoor.ASP.WEBSHELL.AX. 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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