Investigating Compromised Linux Web Server and Potential Dataloss

In the world of cybersecurity and digital forensics, every case presents unique challenges. Recently, I was entrusted with a critical investigation involving a prominent sportswear e-commerce platform based in Thailand. The client had reported the sudden disappearance of core PHP files, raising concerns about the possibility of a cyberattack or an inside job. My mission was clear: recover the deleted files and uncover the identity of the culprit.

The Setting: A Sportswear E-Commerce Giant in Thailand

Our client, a well-known sportswear e-commerce platform in Thailand, faced a severe setback when crucial web application files were mysteriously deleted. This raised two primary concerns: first, the restoration of the lost files, and second, identifying the entity responsible for this act, be it a disgruntled employee or a malicious actor.

Task 1: Data Recovery - A Race Against Time

Challenge 1: File Deletion

The initial challenge was to restore the deleted core PHP files, which were the lifeblood of the e-commerce platform. These files controlled the website's functionality, and their absence rendered the platform inoperable.

Solution 1: Data Recovery Operations

To address this challenge, I initiated data recovery operations. I carefully examined the server logs, notably the /var/log/syslog and /var/log/auth.log, searching for any unusual activities or access. This led to the discovery of a potentially unauthorized login.

Challenge 2: Recovery and Integrity Checks

With a potential point of intrusion identified, the focus shifted to restoring the deleted files. However, the recovery process is needed to ensure the files' integrity and trustworthiness.

Solution 2: File Restoration and Integrity Checks

After confirming the intrusion point, I proceeded to recover the deleted files from backups and checked their integrity. It was crucial to guarantee that the restored files were free from any tampering or malware injection.

Task 2: Investigating the Culprit - Unmasking the Intruder

Challenge 3: Identifying the Culprit

Unmasking the individual or entity behind this incident was the next puzzle to solve. Was it a disgruntled employee or a more sinister force at play?

Solution 3: Digital Forensic Investigation

To identify the culprit, I conducted a comprehensive digital forensic investigation. This involved deep analysis of various logs, file access records, and system activities. Notably, I inspected the /var/log/secure and /var/log/auth.log files for traces of unauthorized access.

Challenge 4: Tracing the Origin

Tracing the origin of the intrusion was pivotal in understanding whether it was an inside job or an external attack. A VPN log audit was particularly insightful.

Solution 4: VPN Log Audit

I carefully reviewed VPN connection logs to identify the source of the intrusion. This log audit revealed that the unauthorized access had originated from an external IP address, suggesting an external actor's involvement.

Challenge 5: Malware and Backdoor Detection

It was essential to inspect the server for any malware or backdoors that the intruder might have planted.

Solution 5: Malware Scanning and Backdoor Detection

I conducted a thorough malware scan using industry-standard tools and meticulously inspected the server's codebase for any suspicious alterations. Fortunately, no malware or backdoors were found.

Conclusion: Restoring the Game

This investigation was a race against time, with the client's business and reputation hanging in the balance. With the files successfully recovered and the culprit unmasked, the e-commerce platform was back in action. The intrusion, as it turned out, was not an inside job, but the work of a malicious external actor. The digital forensic investigation shed light on the source and nature of the attack, allowing for targeted security enhancements. As the world of cybersecurity continually evolves, cases like these reinforce the importance of vigilance and robust incident response strategies in safeguarding digital assets and businesses.