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.(Citation: Outlook File Sizes) IMAP accounts in Outlook 2013 (and earlier) and POP accounts use Outlook Data Files (.pst) as opposed to .ost, whereas IMAP accounts in Outlook 2016 (and later) use .ost files. Both types of Outlook data files are typically stored in C:\Users\<username>\Documents\Outlook Files
or C:\Users\<username>\AppData\Local\Microsoft\Outlook
.(Citation: Microsoft Outlook Files)
Capability ID | Capability Description | Mapping Type | ATT&CK ID | ATT&CK Name |
---|---|---|---|---|
AC-16 | Security and Privacy Attributes | Protects | T1114.001 | Local Email Collection |
AC-17 | Remote Access | Protects | T1114.001 | Local Email Collection |
AC-19 | Access Control for Mobile Devices | Protects | T1114.001 | Local Email Collection |
AC-20 | Use of External Systems | Protects | T1114.001 | Local Email Collection |
AC-4 | Information Flow Enforcement | Protects | T1114.001 | Local Email Collection |
SI-12 | Information Management and Retention | Protects | T1114.001 | Local Email Collection |
SI-4 | System Monitoring | Protects | T1114.001 | Local Email Collection |
SI-7 | Software, Firmware, and Information Integrity | Protects | T1114.001 | Local Email Collection |