Backdoor.ASP.SILOCK.A

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

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 commands from a remote malicious user:

• Depending on the request header parameters, it may execute the following commands:
  • -1: Retrieves Azure information of all files, file owners, file sizes, uploader name and id, folder path and name, and users information from institution database and sent via response header in GZIP stream
  • -2: Deletes "Health Check Service" from users database
  • (no parameter):
    • Retrieves specified folder ID (from header "X-siLocked-Step2") and file ID (from header "X-siLocked-Step3") and sent via response header in GZIP stream
    • Else it adds a new admin user "Health Check Service" in the user database with active session and long timeout.

Information Theft

This Backdoor gathers the following data:

• Azure information
• Information from databases like:
  • files
  • file owners
  • file sizes
  • uploader name and id
  • folder path and name
  • users information from institution database

Other Details

This Backdoor does the following:

• It requires a specific password to be sent in the request headers while accessing the website where it is hosted on.