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workshops/slides/ddos/ddos.md
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DDOS attacks

History

  • Operation Chanology 2008
  • Operation Avenge Assange 2010
  • LOIC
  • Mirai botnet 2017

Distributed vs not distributed

  • vulnerability or bandwidth
  • size of target
  • masses against the powerful

Reverse proxies

  • hidding behind Cloudflare
  • MX records
  • masscan with a Host header
  • finding the hosting provider

Amplification

  • open relays
  • nameservers with a big response (AXFR)
  • method of hidding from the target
  • spoofing IP needed, also ends up hiding from the relay
  • ISPs in Serbia droping them or rewriting them (CGNAT?)
  • don't be stupid

Amplification

Amplification by protocol

SYN Flood

3-way handshake

SYN Flood

  • spoofing doesn't break the attack
  • defense can be configured, but it decreases relibility

Other transmission layer attacks

  • slow read, small TCP receive window
  • TTL expiry, takes more CPU to drop then to forward

HTTP/app based

  • GET of large assests, URI takes relatively a lot of CPU work
  • slow POST
  • maybe search functions, database intensive work (regex?)
  • Slowloris
  • HTTP pipelining, order of requests, have to keep in memory

SSL/TLS

  • renegotiation
  • flood

Vulnerability

  • all bugs in software are usually a DoS vulnerability
  • most common type of CVE by far
  • any layer bug will break the service, finding the weakest link

Network recon

  • sometimes the weakest link is router
  • reverse proxy
  • DNS server? (ignoring the TTL)
  • anything used before connecting to server

Guerrilla warfare tactics

  • making sure the target uses more resources then the attacker
  • getting broad support from the masses
  • spoofing and being hard to find
  • long term fight. losing battles, but winning the war

Government DoS attacks

  • Autistici/Inventati shutdown, censorship with excuse of terrorism
  • Financial derisking isolation, sanctions with excuse of derisking
  • State sponsored flood attacks
  • Arrests, attacking the person behind the service, TPB, Wikileaks

Conclusion

  • don't be afraid, but be careful
  • protest menatality, don't give up, don't let them rest
  • long term results, can't win in a day
  • organize, A/I call for a network called Resistance
  • don't pretend politics have nothing to do with it
  • fight your enemy, not theirs, public support