T1048.002sub-technique of T1048 Exfiltration Over Alternative Protocol
Exfiltration Over Asymmetric Encrypted Non-C2 Protocol
ESXi · Linux · macOS · Windowsnothing on this site yetT1048.002 on attack.mitre.org
Adversaries may steal data by exfiltrating it over an asymmetrically encrypted network protocol other than that of the existing command and control channel. The data may also be sent to an alternate network location from the main command and control server. Asymmetric encryption algorithms are those that use different keys on each end of the channel.
If this is happening now
Checklists and playbooks to open while the alert is still live.
Playbook for this stage
Suspected data theft by an insider
A resignation with unusual file access, a DLP alert, or an unexplained large transfer.
how MITRE says to see it
Detection of Exfiltration Over Asymmetric Encrypted Non-C2 Protocol
- Detects non-browser processes that establish encrypted outbound connections (e.g., TLS/SSL) to unfamiliar or atypical destinations for the host/user, following a data staging or compression event.
- Detects staged file access (e.g., archive or obfuscation), followed by an encrypted outbound connection (TLS/HTTPS) from unusual processes such as curl/wget, Python scripts, or custom binaries.
- Detects abnormal encrypted network connections (via TLS/HTTPS) initiated by non-browser binaries, particularly after sensitive file access or compression events.
- Detects unexpected encrypted outbound connections from management components or guest VMs using TLS, particularly after data volume spikes or script-based orchestration from within guest environments.
what reduces it
- M1031 Network Intrusion Prevention. Network intrusion detection and prevention systems that use network signatures to identify traffic for specific adversary command and control infrastructure and malware can be used to mitigate activity at the network level.
- M1037 Filter Network Traffic. Enforce proxies and use dedicated servers for services such as DNS and only allow those systems to communicate over respective ports/protocols, instead of all systems within a network.
- M1057 Data Loss Prevention. Data loss prevention can detect and block sensitive data being uploaded via web browsers.
- M1030 Network Segmentation. Follow best practices for network firewall configurations to allow only necessary ports and traffic to enter and exit the network.