An Autonomous System (AS) is a network or a group of networks that has a unified routing policy.[^1] Each AS controls a specific set of IP addresses.[^1] They are usually operated by a large organization such as an ISP.[^1] Each Autonomous system is assigned a 16 or 32-bit number (ASN) .[^1] There may be around 100,000 ASNs in use worldwide.[^1] Unexplained tunnels between ASNs may indicate compromise by an APT.[^2] Also specific ASNs may have more malicious activities than others and therefore should not be peered with or routed through.
[[AS Routing Policy]] – list of IP address space that the AS controls and other AS IP addresses
[[Chupa ASN]]
[[ORB Networks]] – rely on geographic ASN providers to reduce reliance on infrastructure in a single country
[[ORB3 (SPACEHOP)]] – registers VPS devices with ASNs
[[Proton66]] – is a Russian Autonomous System
[[Operation Cleaver]] – ad source netblocks and ASNs registered to Iran
[[North Korean Internet]] – North Korean ASN peers to a Russian and Chinese ASN
[[African Initiative]] – has websites hosted on AS 9009
Backlinks
[[Internet]]
[[Internet Service Provider]]
IP Addresses
Sources
[1]Cloudfare_whatIsAnAS
[2] “Countering Chinese State-Sponsored Actors Compromise of Networks Worldwide to Feed Global Espionage System,” Aug. 2025. [Online]. Available: https://media.defense.gov/2025/Aug/22/2003786665/-1/-1/0/CSA_COUNTERING_CHINA_STATE_ACTORS_COMPROMISE_OF_NETWORKS.PDF