Backdoor.ASP.SILOCK.A
Windows
Threat Type: Backdoor
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
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.
TECHNICAL DETAILS
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.
SOLUTION
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.SILOCK.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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