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macOS post-exploitation for credential harvesting, DTrace monitoring, TCC bypass, and stealth operations via native tools
Windows userland post-exploitation for credential harvesting, monitoring, AMSI/ETW bypass, and stealth operations
Kubernetes post-exploitation for container escape, secret extraction, RBAC abuse, and cluster persistence
Based on SOC occupation classification
Showing SKILL.md
| name | cis-ubuntu1804-v220-6-2-4 |
| description | Ensure shadow group is empty |
| category | cis-iam |
| version | 2.2.0 |
| author | cyberstrike-official |
| tags | ["cis","ubuntu","linux","ubuntu-18.04","groups"] |
| cis_id | 6.2.4 |
| cis_benchmark | CIS Ubuntu Linux 18.04 LTS Benchmark v2.2.0 |
| tech_stack | ["ubuntu","linux"] |
| cwe_ids | [] |
| chains_with | [] |
| prerequisites | [] |
| severity_boost | {} |
The shadow group allows system programs which require access the ability to read the /etc/shadow file. No users should be assigned to the shadow group.
Any users assigned to the shadow group would be granted read access to the /etc/shadow file. If attackers can gain read access to the /etc/shadow file, they can easily run a password cracking program against the hashed passwords to break them. Other security information that is stored in the /etc/shadow file (such as expiration) could also be useful to subvert additional user accounts.
Run the following commands and verify no results are returned:
# awk -F: '($1=="shadow") {print $NF}' /etc/group
# awk -F: '($4 == '"$(getent group shadow | awk -F: '{print $3}' | xargs)"') {print " - user: \"" $1 "\" primary group is the shadow group"}' /etc/passwd
No output should be returned.
Run the following command to remove all users from the shadow group:
# sed -ri 's/(^shadow:[^:]*:[^:]*:[^:]*|[^:]+$)/\1/' /etc/group
Change the primary group of any users with shadow as their primary group.
# usermod -g <primary group> <user>