Query: detection engineering for Clear Mailbox Data
Matching passage: T1070.008 Clear Mailbox Data. Tactics: stealth. Description: Adversaries may modify mail and mail application data to remove evidence of their activity. Email applications allow users and other programs to export and delete mailbox data via command line tools or use of APIs. Mail application data can be emails, email metadata, or logs generated by the application or operating system, such as export requests. Adversaries may manipulate emails and mailbox data to remove logs, artifacts, and metadata, such as evidence of [Phishing](https://attack.mitre.org/techniques/T1566)/[Internal Spearphishing](https://attack.mitre.org/techniques/T1534), [Email Collection](https://attack.mitre.org/techniques/T1114), [Mail Protocols](https://attack.mitre.org/techniques/T1071/003) for command and control, or email-based exfiltration such as [Exfiltration Over Alternative Protocol](https://attack.mitre.org/techniques/T1048). For example, to remove evidence on Exchange servers adversaries have used the <code>ExchangePowerShell</code> [PowerShell](https://attack.mitre.org/techniques/T1059/001) module, including <code>Remove-MailboxExportRequest</code> to remove evidence of mailbox exports.(Citation: Volexity SolarWinds)(Citation: ExchangePowerShell Module) On Linux and macOS, adversaries may also delete emails through a command line utility called <code>mail</code> or use [AppleScript](https://attack.mitre.org/techniques/T1059/002) to interact with APIs on macOS.(Citation: Cybereason Cobalt Kitty 2017)(Citation: mailx man page) Adversaries may also remove emails and metadata/headers indicative of spam or suspicious activity (for example, through the use of organization-wide transport rules) to reduce the likelihood of malicious emails being detected by security products.(Citation: Microsoft OAuth Spam 2022)
Near-miss passage: T1070.007 Clear Network Connection History and Configurations. Tactics: stealth. Description: Adversaries may clear or remove evidence of malicious network connections in order to clean up traces of their operations. Configuration settings as well as various artifacts that highlight connection history may be created on a system and/or in application logs from behaviors that require network connections, such as [Remote Services](https://attack.mitre.org/techniques/T1021) or [External Remote Services](https://attack.mitre.org/techniques/T1133). Defenders may use these artifacts to monitor or otherwise analyze network connections created by adversaries. Network connection history may be stored in various locations. For example, RDP connection history may be stored in Windows Registry values under (Citation: Microsoft RDP Removal): * <code>HKEY_CURRENT_USER\Software\Microsoft\Terminal Server Client\Default</code> * <code>HKEY_CURRENT_USER\Software\Microsoft\Terminal Server Client\Servers</code> Windows may also store information about recent RDP connections in files such as <code>C:\Users\\%username%\Documents\Default.rdp</code> and `C:\Users\%username%\AppData\Local\Microsoft\Terminal Server Client\Cache\`.(Citation: Moran RDPieces) Similarly, macOS and Linux hosts may store information highlighting connection history in system logs (such as those stored in `/Library/Logs` and/or `/var/log/`).(Citation: Apple Culprit Access)(Citation: FreeDesktop Journal)(Citation: Apple Unified Log Analysis Remote Login and Screen Sharing) Malicious network connections may also require changes to third-party applications or network configuration settings, such as [Disable or Modify System Firewall](https://attack.mitre.org/techniques/T1686) or tampering to enable [Proxy](https://attack.mitre.org/techniques/T1090). Adversaries may delete or modify this data to conceal indicators and/or impede defensive analysis.