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For many years, Windows users were the only ones at risk of facing malware network security threats; however, cybercriminals have come to view Linux as a viable target for their attacks due to the growing popularity of the open-source OS and the plethora of high-value devices it powers. During 2019 and 2020, dangerous Linux malware variants like CloudSnooper, EvilGnome, and HiddenWasp emerged, and the number of malware strains continued to grow over time as Linux malware operators harbored great success with their malicious malware and phishing campaigns. Thus, taking proactive measures to secure your Linux systems against attacks has never been more critical.

Reverse engineering seeks to deconstruct malware in an artificial environment, such as a Linux system, to gain insight into its design, architecture, and code. It is a highly effective method of malware detection and analysis, which we will examine in this article, highlighting how reverse engineering can be used to secure Linux systems,  our favorite network security toolkits for doing so, and malware scanning available to Linux users.

How Can Reverse Engineering Detect, Analyze, and Protect against Malware for Ultimate Security?

Reverse Engineering1Reverse engineering helps administrators identify, study, and eliminate network security issues and risks on their systems that they can use to gain knowledge on how to prevent future attacks in network security. This process involves disassembling - and sometimes decompiling - malware software programs that threaten to harm a system. By converting binary instructions to code mnemonics (shortcuts within a system) or higher-level constructs, reverse engineers (often referred to as “reversers”) can analyze the characteristics of a malicious program, including its behavior, systems it impacts, and cybersecurity vulnerabilities it exploits. These valuable details can be used to create effective solutions to mitigate the program’s intended malicious results.

Dynamic analysis relies on privacy sandboxing malware testing to determine the speed and automation offered through reverse engineering. Privacy sandboxing is when a malicious program is intentionally launched into a secure environment so companies can find and fix the cybersecurity vulnerabilities within their system. As emerging malware strains continue to demonstrate increasingly complex techniques, reversers need more time to understand disassembled or decompiled code, which can be an opportunity for cybercriminals to compromise a network with malware. The use of dynamic analysis can make reverse engineering more efficient and effective; however, reversers should not rely solely on dynamic techniques, as sophisticated malware variants are capable of employing evasion techniques that detect whether they are in a sandbox, allowing them the chance to delay or hide malicious activities.

The best approach to malware detection and analysis involves combining the previously described methods to work automatically to combat any threat heading a company’s way. Dynamic analysis can be used to automatically analyze the majority of network security threats, while reversers can dedicate their time to acquiring threat intelligence from the most sophisticated attacks.

Now that we’ve explored how reverse engineering can help you secure your Linux systems against malware, we can go over the various network security toolkits and utilities that can assist in the process of reverse engineering and malware scanning.

Network Security Toolkits and Utilities to Use with Linux Reverse Engineering & Malware Scanning

REMnux

REMnux is a free, versatile network security toolkit that conveniently allows reversers and analysts to investigate malware without having to find, install, and configure the tools needed. REMnux offers a distro that can be downloaded as a Virtual Machine (VM) in the OVO format and then imported into your hypervisor, installed from scratch on a dedicated host, added to an existing system running a compatible version of Ubuntu, or run as a Docker container.

Chkrootkit

Chkrootkit is a widely used free rootkit detector. A rootkit is a malware program that gives cyber criminals access to a system from afar. This protection toolkit locally scans for rootkits and hidden security holes on Unix/Linux systems utilizing a shell script that checks system binaries for any rootkit modification through the use of “strings” and “grep” (Linux tool commands) to detect potential network security threats. Chkrootkit can verify an already compromised system through alternative directories or rescue discs. It can also locate deleted entries in the “wtmp” and “lastlog” files, find sniffer records or rootkit configuration files, check for hidden entries in “/proc,” and look at calls to the “readdir” program. Chkrootkit can be downloaded here.

Rkhunter

Rkhunter is a powerful, user-friendly tool designed to inspect and analyze Linux systems for hidden security holes and scan for rootkits, backdoors, and local exploits in cybersecurity. This tool thoroughly checks files, default directories, kernel modules, and misconfigured permissions, comparing them to the database records that can help identify suspicious programs. Rkhunter can be downloaded here.

Lynis

Lynis is a popular, free malware scanning and auditing tool for Unix/Linux OSes used to detect security holes and configuration flaws, which could be cybersecurity vulnerabilities. It performs firewall auditing, checks file/directory permissions and integrity, and verifies installed software. Lynis exposes network security threats but provides mitigation suggestions to assist you in taking care of your system. Lynis can be downloaded here. 

LMD

Linux Malware Detect (LMD) is a full-featured malware and cloud security scanner explicitly designed for hosted environments; however, LMD can be used to detect network security threats on any Linux system. The renowned program uses a signature database to identify and rapidly terminate malicious code running on a system. To populate its database, LMD captures threat intelligence data from network edge Intrusion Detection Systems (IDS), enabling programs to generate new signatures for malware actively being used in attacks. LMD includes a complete reporting system where administrators can view current and past scan results and receive email alerts after each scan. To improve LMD’s performance, you can integrate it alongside the virus scanner, ClamAV.

Keep Learning about Mitigating Network Security Threats

Reverseengineerinf2Malware is a growing concern for administrators as the prevalence and sophistication of variants targeting Linux systems continue to increase. However, this tends to result from misconfigured servers and poor administration, demonstrating that this rise in attacks is not a result of defective data and network security on Linux’s part.

Testing and verifying server cybersecurity projects on an ongoing basis is crucial to preventing attacks. Reverse engineering is an excellent method of detecting and analyzing malware on Linux systems and gathering threat intelligence that can be used to prevent future network security issues. There are various services for reverse engineering and malware scanning available to Linux users that are powerful, user-friendly, and free to download.

Have questions about reverse engineering? Currently, are you using one or more of the network security toolkits that we’ve highlighted in this article? We'd love to hear about your experience and/or answer your questions! Please do not hesitate to contact us on social media: Twitter | Facebook