Hackfest 2023 - Back to the Future

MITM on PSTN -- novel methods for intercepting phone calls
2023-10-13, 17:30–17:50, Track #2

In this talk the author proposes a novel method for intercepting phone calls over PSTN, including mobile networks.
We'll briefly each discuss the necessary components of the attack, including Caller ID spoofing, SS7, call diverts, and social engineering, and then join the all together to form the novel attack method.

Two separate methods will be proposed.
The author will provide a pre-recorded demo of each attack.

  1. PSTN / MN / CLIP / CNAM
  2. SS7 features and attacks
  3. Relevant social engineering techniques
  4. Attack 1: Simultaneous ring attack
  5. Attack 2: Diversion attack
  6. Tactic 1: Interception of phone calls
  7. Tactic 2: Alteration of phone calls (content)
  8. Tactic 2: Alteration of phone calls (metadata)
  9. Proposed solutions

Note that the presentation includes pre-recorded demos as it's ill-advised to do this live in a conference for legal reasons.

Are you releasing a tool? – No