Analysis by: John Rainier Navato
 PLATFORM:

Windows

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

  • Threat Type: Trojan Spy

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

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

This Trojan Spy 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: 1,194 bytes
File Type: JS
Memory Resident: No
Initial Samples Received Date: 02 Apr 2026
Payload: Connects to URLs/IPs, Steals information

Arrival Details

This Trojan Spy 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 Trojan Spy connects to the following URL(s) to download its component file(s):

Information Theft

This Trojan Spy gathers the following data:

  • Current web browser URL
  • All browser cookies
  • Any webpage input field value
  • Entire browser localStorage contents
  • Entire browser sessionStorage contents
  • Browser master encryption keys (from Local State files)

Stolen Information

This Trojan Spy sends the gathered information via HTTP POST to the following URL:

  • https://{BLOCKED}k.is/{BLOCKED}.php

Other Details

This Trojan Spy does the following:

  • It selects all input fields and editable content elements in the current webpage to capture form input values.
  • It dumps the target browser's entire localStorage.
  • It dumps the target browser's entire sessionStorage.

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 20.862.01
FIRST VSAPI PATTERN DATE: 02 Apr 2026
VSAPI OPR PATTERN File: 20.863.00
VSAPI OPR PATTERN Date: 02 Apr 2026

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 TrojanSpy.JS.WEIFRAIBO.A. 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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