A Linux machine running an Apache web server(accessible to LAN clients) has its anti-virus (AV) software expired. What scenarios we need to concern?
A Linux Apache server with expired antivirus loses a critical defense layer, making it susceptible to stealthy attacks like backdoor scripts, brute-force attempts, and zero-day exploits targeting web applications.

Security Risks

Malware intrusion via Web Uploads

Risk

File upload bypass: Malicious actors upload executable files (.php, .sh, .py) through:
Vulnerable web forms (e.g., WordPress plugins, custom upload scripts)
Compromised admin interfaces

Impact

1. Automated execution of scripts
2. Data exfiltration(Data theft): Attacker steal sensitive data(e.g.,databases password in .env file, config files with credentials, SSH keys)
3. ransomware deployment(e.g. attackers encrypt files under web directory such as /var/www/html, making the websiste/content inaccessible until a ransom is paid).
4. Open backdoor remote access(e.g.,Trojans)

Mitigation Steps

1. File upload hardening.
2. Use containers (Docker) to isolate Apache with read-only volumes for /var/www/html.
3. Filesystem protection via restrict ownership.
4. Frontend, add WAF.

Exploiting Unpatched Vulnerabilities

Risk

Zero day attacks: expired AV misses new malware signatures.
Attacker exploit known apache software vulnerability. Since antivirus software is outdated, so antivirus signature didn’t update and cannot detect new format of virus.

Mitigation Steps

1. Renew/update Anti-Virus protection and OS system regularly

LAN propagation

Risk

Infected clients (e.g., Windows PCs) may spread worms via:

• SMB exploits (e.g., EternalBlue).
• Credential brute-forcing (e.g., SSH/RDP(Remote Desktop Protocol) from compromised server).

Mitigation Steps

1. Segment LAN: place the server in DMZ or VLAN