TA0005 · DEFENSE EVASION
Reduce Key Space
Adversaries may reduce the level of effort required to decrypt data transmitted over the network by reducing the cipher strength of encrypted communications.
Detect it with
There is no documented method for defenders to directly identify behaviors that reduce encryption key space. Detection efforts may be focused on closely related adversary behaviors, such as Modify System Image and Network Device CLI.
Why it matters on shift
Reduce Key Space is one of the concrete ways adversaries achieve defense evasion. Recognising it in telemetry lets you name the technique in your ticket and pivot to what came before and after.
What to look for next
After defense evasion, the next tactic is usually Credential Access. Search your telemetry for the transition before closing the ticket.
Kill-chain context