2 weeks ago

1.7 Tbps DDoS Attack — ​Memcached UDP Reflections Set brand new Record


The bar has been raised.

As more amplified attacks were expected following the record-breaking 1.35 Tbps Github DDoS attack, someone has just set a brand new record after only four days — 1.7 Tbps DDoS attack.

Network security in addition to also also monitoring company Arbor Networks claims that will its ATLAS global traffic in addition to also also DDoS threat data system have recorded a 1.7Tbps reflection/amplification attack against one of its unnamed US-based customer’s website.

Similar to the last week’s DDoS attack on GitHub, the massive bandwidth of the latest attack was amplified by a factor of 51,000 using thousands of misconfigured Memcached servers exposed on the Internet.

Memcached, a favorite open source distributed memory caching system, came into news earlier last week when researchers detailed how attackers could abuse that will to launch amplification DDoS attack by sending a forged request to the targeted Memcached server on port 11211 using a spoofed IP address that will matches the victim’s IP.

A few bytes of the request sent to the vulnerable server can trigger tens of thousands of times bigger response against the targeted IP address, resulting in a powerful DDoS attack.


Meanwhile, researchers also noted that will cybercriminals have started out weaponizing the DDoS attacks through vulnerable memcached servers to extort money via victims.

Following last week’s 1.3 Tbps DDoS attack against GitHub, Akamai said its customers have been receiving extortion messages delivered alongside the typically “junk-filled” attack payloads, asking them for 50 XMR (Monero coins), valued at over $15,000.

“While the internet community will be coming together to shut down access to the many open memcached servers out there, the sheer number of servers running memcached openly will make This kind of a lasting vulnerability that will attackers will exploit,” Arbor Networks said in a blog post.

Reflection/amplification attacks are not brand new. Attackers have previously used reflection/amplification DDoS attack techniques to exploit flaws in DNS, NTP, SNMP, SSDP, CLDAP, Chargen in addition to also also some other protocols in an attempt to maximize the scale of their cyber attacks.

However, the latest attack vector evolves thousands of misconfigured Memcached servers, many of which are still exposed on the Internet in addition to also also could be exploited to launch potentially more massive attacks soon against some other targets. So expect to see more such attacks in coming days.

To prevent Memcached servers via being abused as reflectors, we urge users to install a firewall that will should provide access to memcached servers only via the local network.

Administrators should also consider avoiding external traffic to the ports used by memcached (for example 11211 port used by default), in addition to also also block or rate-limiting UDP or completely disable UDP support if not in use.

Article Categories:
Security Hacks

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