Malware Distribution by Autonomous System

Safe Browsing scans millions of websites to identify those sites that install malware without a user's knowledge. We discover and categorize these sites by autonomous system (AS) numbers, thousands of which exist on the Internet.

This data is part of our effort to support a safer and more secure web. By sharing information from our scans, we hope to encourage cooperation among those who battle malware. See our FAQ for more about Google’s efforts to help networks combat malware.


Information by Autonomous System

This table lists malware distribution among autonomous systems scanned by Safe Browsing within a selected region for a given time period. Because Safe Browsing’s scanners are designed to seek out malware, they may only scan a small fraction of each AS, shown in the far right column. Filter by size to see all or only large autonomous systems. Both attack sites and compromised sites are displayed by default.


Time range

Autonomous Systems


Type of Site Detected

Compromised Sites
Attack Sites
Autonomous System Number of sites scanned Scanned sites hosting malware % of AS scanned

Scan History by Autonomous System

This chart depicts malware distribution based on the percentage of the AS our systems scan over time. The percentage of sites that we scan is directly affected by changes to our sampling algorithms, so we also provide a view of the number of scanned sites where we detect malware. You may see spikes in these charts because the success of various malware techniques can shift rapidly.