Does successful decryption prove the incident is over?¶

No. Decryption restores some data availability; it does not prove containment, system trust, deletion of stolen data or the end of extortion.

Verify access removal separately¶

Continue examining the initial route, privileged accounts, sessions, tokens, application consent, malware, web shells, remote tools, tasks and cloud or management platforms. A restored workstation can reconnect to a compromised identity or administration service.

Check each mechanism across the environment rather than assuming recovery of one host removed it. Monitor for new sign-ins, token use, account changes, reconnection and command traffic.

Preserve the pre-recovery state¶

Decryptors can alter files, timestamps and system records, while renewed business activity can obscure older evidence. Retain representative encrypted originals and record every recovery change.

Data may already be held elsewhere and used for continuing pressure. Investigate collection and exfiltration independently of restored files, and assess containment using its own evidence.