MITRE ATT&CKsub-technique

T1003.008 /etc/passwd and /etc/shadow

Published 2020-02-11 Modified 2025-10-24 Official page ↗
Domain
enterprise
Tactics
Credential Access
Platforms
Linux
Version
1.2
Created
2020-02-11

Description

Adversaries may attempt to dump the contents of /etc/passwd and /etc/shadow to enable offline password cracking. Most modern Linux operating systems use a combination of /etc/passwd and /etc/shadow to store user account information, including password hashes in /etc/shadow. By default, /etc/shadow is only readable by the root user. Linux stores user information such as user ID, group ID, home directory path, and login shell in /etc/passwd. A "user" on the system may belong to a person or a service. All password hashes are stored in /etc/shadow - including entries for users with no passwords and users with locked or disabled accounts. Adversaries may attempt to read or dump the /etc/passwd and /etc/shadow files on Linux systems via command line utilities such as the cat command. Additionally, the Linux utility unshadow can be used to combine the two files in a format suited for password cracking utilities such as John the Ripper - for example, via the command /usr/bin/unshadow /etc/passwd /etc/shadow > /tmp/crack.password.db. Since the user information stored in /etc/passwd are linked to the password hashes in /etc/shadow, an adversary would need to have access to both.

Related

Subtechnique of · MITRE ATT&CK (1)

  • T1003 OS Credential Dumping technique

Tactic · MITRE ATT&CK (1)

  • TA0006 Credential Access tactic

Referenced by MITRE ATT&CK · mitigates (2)

  • M1026 Privileged Account Management mitigation
  • M1027 Password Policies mitigation

Referenced by MITRE ATT&CK · uses (3)

  • C0064 AI-Assisted Breach of Mexico's Government Infrastructure campaign
  • C0045 ShadowRay campaign
  • S0349 LaZagne software (tool)

Referenced by Compliance · mitigates (14)

  • NIST-AC-2 Account Management NIST 800-53 control
  • NIST-AC-3 Access Enforcement NIST 800-53 control
  • NIST-AC-5 Separation of Duties NIST 800-53 control
  • NIST-AC-6 Least Privilege NIST 800-53 control
  • NIST-CA-7 Continuous Monitoring NIST 800-53 control
  • NIST-CM-2 Baseline Configuration NIST 800-53 control
  • NIST-CM-5 Access Restrictions for Change NIST 800-53 control
  • NIST-CM-6 Configuration Settings NIST 800-53 control
  • NIST-IA-2 Identification and Authentication (Organizational Users) NIST 800-53 control
  • NIST-IA-5 Authenticator Management NIST 800-53 control
  • NIST-SC-28 Protection of Information at Rest NIST 800-53 control
  • NIST-SC-39 Process Isolation NIST 800-53 control
  • NIST-SI-3 Malicious Code Protection NIST 800-53 control
  • NIST-SI-4 System Monitoring NIST 800-53 control

References