T1685.006 · defense-impairment · ATT&CK 19.1

Clear Linux or Mac System Logs

Adversaries may clear system logs to hide evidence of an intrusion. macOS and Linux both keep track of system or user-initiated actions via system logs. The majority of native system logging is stored under the `/var/log/` directory. Subfolders in this directory categorize logs by their related functions, such as:(Citation: Linux Logs) * `/var/log/messages:`: General and system-related messages * `/var/log/secure or /var/log/auth.log`: Authentication logs * `/var/log/utmp or /var/log/wtmp`: Login records * `/var/log/kern.log`: Kernel logs * `/var/log/cron.log`: Crond logs * `/var/log/maillog`: Mail server logs * `/var/log/httpd/`: Web server access and error logs

Open in the interactive knowledge mesh

Detection overview

Use the published detection strategies below and validate required telemetry in the target environment.

Observed groups

Cyber Knowledge context

Use these routes to move from the ATT&CK behavior into explanation, implementation, evidence handling, validation, and defensive operations. Relevance is generated from explicit identifiers/names and governed topic mappings; it is not attribution evidence.

MITRE mitigations

M1022 · Restrict File and Directory Permissions

Restricting file and directory permissions involves setting access controls at the file system level to limit which users, groups, or processes can read, write, or execute files. By configuring permissions appropriately, organizations can reduce the attack surface for adversaries seeking to access sensitive data, plant malicious code, or tamper with system files. Enforce Least Privilege Permissions: - Remove unnecessary write permissions on sensitive files and directories. - Use file ownership and groups to control access for specific roles. Example (Windows): Right-click the shared folder → Properties → Security tab → Adjust permissions for NTFS ACLs. Harden File Shares: - Disable anonymous access to shared folders. - Enforce NTFS permissions for shared folders on Windows. Example: Set permissions to restrict write access to critical files, such as system executables (e.g., `/bin` or `…

MITRE mitigation source
M1029 · Remote Data Storage

Remote Data Storage focuses on moving critical data, such as security logs and sensitive files, to secure, off-host locations to minimize unauthorized access, tampering, or destruction by adversaries. By leveraging remote storage solutions, organizations enhance the protection of forensic evidence, sensitive information, and monitoring data. This mitigation can be implemented through the following measures: Centralized Log Management: - Configure endpoints to forward security logs to a centralized log collector or SIEM. - Use tools like Splunk Graylog, or Security Onion to aggregate and store logs. - Example command (Linux): `sudo auditd | tee /var/log/audit/audit.log | nc <remote-log-server> 514` Remote File Storage Solutions: - Utilize cloud storage solutions like AWS S3, Google Cloud Storage, or Azure Blob Storage for sensitive data. - Ensure proper encryption at rest and access cont…

MITRE mitigation source
M1041 · Encrypt Sensitive Information

Protect sensitive information at rest, in transit, and during processing by using strong encryption algorithms. Encryption ensures the confidentiality and integrity of data, preventing unauthorized access or tampering. This mitigation can be implemented through the following measures: Encrypt Data at Rest: - Use Case: Use full-disk encryption or file-level encryption to secure sensitive data stored on devices. - Implementation: Implement BitLocker for Windows systems or FileVault for macOS devices to encrypt hard drives. Encrypt Data in Transit: - Use Case: Use secure communication protocols (e.g., TLS, HTTPS) to encrypt sensitive data as it travels over networks. - Implementation: Enable HTTPS for all web applications and configure mail servers to enforce STARTTLS for email encryption. Encrypt Backups: - Use Case: Ensure that backup data is encrypted both during storage and transfer to…

MITRE mitigation source

MITRE detection strategies and analytics

DET0520 · Behavioral Detection of Log File Clearing on Linux and macOS
  • AN1438 · Analytic 1438 — Detects log-clearing behavior by correlating suspicious command execution targeting log files under /var/log/, anomalous deletions or truncations of system logs, and unusual child processes (e.g., shell pipelines or redirections).
  • AN1439 · Analytic 1439 — Detects adversary clearing log files on macOS by correlating calls to shell utilities (e.g., echo >, rm, truncate) targeting files in /var/log/ with unusual context (non-administrative users or abnormal process lineage).
MITRE detection source