What is Exfiltration?
Data exfiltration is the unauthorized transfer of sensitive data from a victim environment to attacker-controlled infrastructure, the stage where intellectual property, credentials, customer data, or other valuable information is stolen.
Definition
- Exfiltration
- Data exfiltration is the unauthorized transfer of sensitive data from a victim environment to attacker-controlled infrastructure, the stage where intellectual property, credentials, customer data, or other valuable information is stolen.
How Exfiltration Works
Exfiltration typically occurs after the attacker has sufficient access. Before exfiltrating, attackers stage data: collecting files from across the network, compressing them, and sometimes encrypting them to avoid content inspection.
Exfiltration channels: HTTPS to cloud storage (Dropbox, OneDrive, Google Drive) is common because these services are whitelisted at the firewall. DNS exfiltration encodes data in query names (base64 as subdomains). Physical exfiltration uses USB drives. Email exfiltration sends data to personal accounts.
DLP systems detect and block exfiltration. Network monitoring looks for large outbound transfers, connections to cloud storage from unusual processes, and anomalous outbound DNS traffic volume. UEBA tracks data access patterns and alerts when users access far more data than their baseline.
Exfiltration in SOC Operations
Detecting exfiltration in progress, before the transfer completes, can prevent the most damaging outcome of a breach. Watch for large outbound transfers to cloud services, DNS anomalies (high query volumes to single external domains), and DLP alerts on sensitive data categories. When exfiltration is confirmed or suspected, immediate containment (blocking the connection, isolating the host) is critical.
Practice Exfiltration in a Real SOC
SOCSimulator provides hands-on training with realistic SIEM, XDR, and Firewall interfaces. Build real analyst skills investigating exfiltration scenarios with zero consequences — free forever.
Related Terms
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More Threats Terms
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