Internet companies Google, Amazon and Cloudflare say they have weathered the internet’s largest-known denial-of-service attack and are sounding the alarm over a new technique they warn could easily cause widespread disruption.

Google said in a blog post on Tuesday that its cloud services had parried an avalanche of rogue traffic more than seven times the size of the previous record-breaking attack thwarted last year.

Internet protection company Cloudflare said the attack was “three times larger than any previous attack we’ve observed”. Amazon.com’s web services division also confirmed being hit by “a new type of distributed denial of service (DDoS) event”.

All three said the attack began in late August; Google said it was ongoing.

Denial of service is among the web’s most basic form of attack and it works by simply overwhelming targeted servers with a firehose of bogus requests for data, making it impossible for legitimate web traffic to get through.

As the online world has developed, so, too, has the power of denial-of-service operations, some of which can generate millions of bogus requests per second. The recent attacks measured by Google, Cloudflare and Amazon were capable of generating hundreds of millions of request per second.

Google said in its blog post that only two minutes of one such attack “generated more requests than the total number of article views reported by Wikipedia during the entire month of September 2023”. Cloudflare said the attack was of a magnitude that “has never been seen before”.

Supersized DDoS

All three companies said the supersized attacks were enabled by a weakness in HTTP/2 — a newer version of the HTTP network protocol that underpins the web — that makes servers particularly vulnerable to rogue requests.

The firms urged companies to update their web servers to ensure that they do not remain vulnerable.

None of the three companies said who was responsible for the DDoS attacks, which have historically been difficult to pin down.

Read: Microsoft says service outages were result of cyberattacks

If cleverly aimed and not successfully countered, such attacks can lead to widespread disruption. In 2016, an attack attributed to the “Mirai” network of hijacked devices hit domain name service Dyn, disrupting a swath of high profile websites. — Raphael Satter, (c) 2023 Reuters