# Find all successful SSH logins
grep "Accepted" /var/log/auth.log

# Find failed SSH login attempts
grep "Failed password" /var/log/auth.log

# Extract unique source IPs from failed logins
grep "Failed password" /var/log/auth.log | grep -oP '\d+\.\d+\.\d+\.\d+' | sort -u

# Find sudo command execution
grep "sudo:" /var/log/auth.log | grep "COMMAND"

# Detect brute force patterns (>10 failures from same IP)
grep "Failed password" /var/log/auth.log | awk '{print $(NF-3)}' | sort | uniq -c | sort -rn | head -20

# Find account creation events
grep "useradd\|adduser" /var/log/auth.log

# Detect SSH key authentication
grep "Accepted publickey" /var/log/auth.log

# Export journal in JSON format for forensic processing
journalctl --output=json --no-pager > journal_export.json

# Filter by time range
journalctl --since "2025-02-01" --until "2025-02-15" --output=json > timerange.json

# Filter by unit/service
journalctl -u sshd --output=json > sshd_journal.json

# Show kernel messages (USB events, module loads)
journalctl -k --output=json > kernel_journal.json

# Filter by priority (0=emerg to 7=debug)
journalctl -p err --output=json > errors.json

# Boot-specific logs
journalctl -b 0 --output=json > current_boot.json
journalctl --list-boots  # List all recorded boot sessions

# Search audit log for specific event types
ausearch -m USER_AUTH --start today

# Search for file access events
ausearch -f /etc/shadow

# Search for process execution
ausearch -m EXECVE --start "02/01/2025" --end "02/28/2025"

# Generate report of login events
aureport --login --start "02/01/2025"

# Generate summary of failed authentications
aureport --auth --failed

# Search for specific user activity
ausearch -ua 1001  # By UID
ausearch -ua username  # By username

# Check system-wide crontab
cat /etc/crontab

# Check user crontabs
ls -la /var/spool/cron/crontabs/

# Review cron execution logs
grep "CRON" /var/log/syslog

# Check for at/batch jobs
ls -la /var/spool/at/
atq

import re
import json
import sys
import os
from datetime import datetime
from collections import defaultdict


class LinuxLogForensicAnalyzer:
    """Analyze Linux system logs for forensic investigation."""

    def __init__(self, log_dir: str, output_dir: str):
        self.log_dir = log_dir
        self.output_dir = output_dir
        os.makedirs(output_dir, exist_ok=True)

    def parse_auth_log(self, auth_log_path: str) -> dict:
        """Parse auth.log for authentication events."""
        events = {
            "successful_logins": [],
            "failed_logins": [],
            "sudo_commands": [],
            "account_changes": [],
            "ssh_sessions": []
        }

        ssh_accepted = re.compile(
            r'(\w+\s+\d+\s+[\d:]+)\s+(\S+)\s+sshd\[\d+\]:\s+Accepted\s+(\S+)\s+for\s+(\S+)\s+from\s+([\d.]+)'
        )
        ssh_failed = re.compile(
            r'(\w+\s+\d+\s+[\d:]+)\s+(\S+)\s+sshd\[\d+\]:\s+Failed\s+password\s+for\s+(\S*)\s+from\s+([\d.]+)'
        )
        sudo_cmd = re.compile(
            r'(\w+\s+\d+\s+[\d:]+)\s+(\S+)\s+sudo:\s+(\S+)\s+:.*COMMAND=(.*)'
        )
        useradd = re.compile(
            r'(\w+\s+\d+\s+[\d:]+)\s+(\S+)\s+useradd\[\d+\]:\s+new user: name=(\S+)'
        )

        with open(auth_log_path, "r", errors="replace") as f:
            for line in f:
                m = ssh_accepted.search(line)
                if m:
                    events["successful_logins"].append({
                        "timestamp": m.group(1), "host": m.group(2),
                        "method": m.group(3), "user": m.group(4), "source_ip": m.group(5)
                    })
                    continue

                m = ssh_failed.search(line)
                if m:
                    events["failed_logins"].append({
                        "timestamp": m.group(1), "host": m.group(2),
                        "user": m.group(3), "source_ip": m.group(4)
                    })
                    continue

                m = sudo_cmd.search(line)
                if m:
                    events["sudo_commands"].append({
                        "timestamp": m.group(1), "host": m.group(2),
                        "user": m.group(3), "command": m.group(4).strip()
                    })
                    continue

                m = useradd.search(line)
                if m:
                    events["account_changes"].append({
                        "timestamp": m.group(1), "host": m.group(2),
                        "new_user": m.group(3)
                    })

        return events

    def detect_brute_force(self, auth_events: dict, threshold: int = 10) -> list:
        """Detect brute force attempts from auth log data."""
        ip_failures = defaultdict(int)
        for event in auth_events.get("failed_logins", []):
            ip_failures[event["source_ip"]] += 1

        brute_force = []
        for ip, count in ip_failures.items():
            if count >= threshold:
                brute_force.append({"source_ip": ip, "failed_attempts": count})

        return sorted(brute_force, key=lambda x: x["failed_attempts"], reverse=True)

    def generate_report(self, auth_log_path: str) -> str:
        """Generate comprehensive forensic analysis report."""
        auth_events = self.parse_auth_log(auth_log_path)
        brute_force = self.detect_brute_force(auth_events)

        report = {
            "analysis_timestamp": datetime.now().isoformat(),
            "log_source": auth_log_path,
            "summary": {
                "successful_logins": len(auth_events["successful_logins"]),
                "failed_logins": len(auth_events["failed_logins"]),
                "sudo_commands": len(auth_events["sudo_commands"]),
                "account_changes": len(auth_events["account_changes"]),
                "brute_force_sources": len(brute_force)
            },
            "brute_force_detected": brute_force,
            "auth_events": auth_events
        }

        report_path = os.path.join(self.output_dir, "linux_log_forensics.json")
        with open(report_path, "w") as f:
            json.dump(report, f, indent=2)

        print(f"[*] Successful logins: {report['summary']['successful_logins']}")
        print(f"[*] Failed logins: {report['summary']['failed_logins']}")
        print(f"[*] Sudo commands: {report['summary']['sudo_commands']}")
        print(f"[*] Brute force sources: {report['summary']['brute_force_sources']}")
        return report_path


def main():
    if len(sys.argv) < 3:
        print("Usage: python process.py <auth_log_path> <output_dir>")
        sys.exit(1)
    analyzer = LinuxLogForensicAnalyzer(os.path.dirname(sys.argv[1]), sys.argv[2])
    analyzer.generate_report(sys.argv[1])


if __name__ == "__main__":
    main()