T1114.001sub-technique of T1114 Email Collection
Local Email Collection
Windowsnothing on this site yetT1114.001 on attack.mitre.org
Adversaries may target user email on local systems to collect sensitive information. Files containing email data can be acquired from a user’s local system, such as Outlook storage or cache files. Outlook stores data locally in offline data files with an extension of.ost. Outlook 2010 and later supports.ost file sizes up to 50GB, while earlier versions of Outlook support up to 20GB.
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
Detect Local Email Collection via Outlook Data File Access and Command Line Tooling
- Detection focuses on processes that attempt to locate, access, or exfiltrate local Outlook data files (.pst/.ost) using file system access, native Windows utilities (e.g., PowerShell, WMI), or remote access tools with file browsing capabilities.
what reduces it
- M1060 Out-of-Band Communications Channel. Implement secure out-of-band alerts to notify security teams of unusual local email activities, such as mass forwarding or large attachments being sent, indicating potential data exfiltration attempts.
- M1041 Encrypt Sensitive Information. Use of encryption provides an added layer of security to sensitive information sent over email. Encryption using public key cryptography requires the adversary to obtain the private certificate along with an encryption key to decrypt messages.