### Overview
The detection of forged cookies has been followed by evidence of **persistence mechanisms** being activated. These mechanisms are designed to maintain access to compromised systems even after initial detection.

### Techniques Identified
- **Backdoor Installation:** Attackers have installed backdoors on Yahoo's servers, allowing remote access at will.
- **Credential Harvesting:** Compromised credentials are being stored for future use, enabling continued account access.

### Threat Actor Insight
These mechanisms suggest a methodical approach typical of state-sponsored groups, who prioritize long-term infiltration.

### Next Steps
Investigate potential lateral movement as attackers seek to expand their access to other accounts and systems.