What Are Fileless Malware Attacks?

Cybercriminals are relentless in their quest to create new ways to circumvent cybersecurity and breach networks. Fileless Attacks are one of the hardest hacks to detect and are potentially the most dangerous methods hackers use. They present serious challenges to network security. Fileless attacks utilize malicious software that works through trusted and frequently used programs already built into a system to evade cybersecurity and infect computers. The common name for hacking using tools already in the system is “living off the land.”

Q: What is fileless malware?

A: It’s a type of malicious software that operates without leaving traditional files on the hard drive, making it more difficult for antivirus programs to detect. Instead of relying on files, it exploits legitimate tools and processes already present on a system to carry out attacks directly in memory.

Because hackers don’t need to embed files to achieve their nefarious goals, fileless malware detection is challenging. There is no signature left behind for detection by typical antivirus software. The malicious code for fileless attacks is stored directly in a computer’s main memory, not on its hard drive. Only professional cybersecurity teams can detect and protect against such attacks.

For example, one of the most popular fileless malware attacks targets Microsoft PowerShell. To hackers, PowerShell has all the features required for an attack:

• Trusted and Frequently Used – PowerShell is widely used by company system administrators
• Factory-Installed in Windows – PowerShell is a default program that comes pre-installed in Windows
• Easy to Hide and Disguise – Attacks through PowerShell are difficult to detect using traditional forms of virus detection and cybersecurity platforms
• Automatically Affords Remote Access – Grants the cybercriminal remote access by default, so hackers in another country can sit in the comfort of their own homes manipulating your system and breaching your data.

Q: How does fileless malware infect systems?

A: Unlike traditional malware, fileless attacks often begin with phishing emails or malicious links that exploit vulnerabilities or trick users into running scripts. Once initiated, the malware uses system tools to drop its payload in memory, leaving few traces and no files that can be easily scanned or quarantined by conventional antivirus software.

What’s the Best Method of Fileless Malware Detection?

Fortunately, fileless malware attacks, although much more complicated to uncover than typical cyberattacks, are not entirely undetectable. One of the most effective methods for early detection of fileless attacks is through endpoint system security monitoring.

Monitoring memory usage and other events related to performing specific software actions on a system can indicate a potential threat. For example, initiating actions such as configuring a script to launch upon log-in, privilege escalations, delivery of payloads, evasion and reconnaissance are all potential parts of this threat. In addition, consistent monitoring by knowledgeable cybersecurity experts can spot unusual memory spikes, cyber events inconsistent with normal operations and other unusual changes.

An IT professional can also monitor your system for suspicious commands and excessive network communications prompted by processes that are not typical for the regular operation of the system. Also, the hackers might try to delete their bash history (the log of commands run by a user) or install malicious browser extensions. Ultimately, early detection is possible only through the tedious process of spotting anomalous behaviors in your system quickly.

Q: Why is fileless malware hard to detect?

A: Fileless malware is difficult to detect because it doesn't install anything that can be scanned or hashed. It blends in with legitimate processes and doesn't leave behind telltale signatures on the file system. Detection usually requires behavioral analysis and memory forensics, which are more complex and less common in standard security setups.

How Should Small Businesses Take On Fileless Malware Removal?

A fileless attack can be “living” in a system’s main memory. Therefore, a complete shutdown is an important first step, since it clears the memory. However, shutting down is not nearly enough to ensure fileless malware removal. There are cybersecurity tools and protocols that can detect fileless hacks to help prevent possible damage. However, these tools are best used by cybersecurity professionals. Defending against fileless attacks requires 24/7 monitoring and the knowledge to spot irregular system activities. After that, security experts can isolate the compromised endpoint from the rest of the system as quickly as possible to mitigate the consequences.

Choose security software with live security operations center monitoring. This type of protection catches unusual network activity (large uploads, activity at odd hours or off days) and alerts a human expert to evaluate. The threat is then investigated. If it is deemed a true threat rather than a false alarm, your cybersecurity provider is notified of the emergency.

Fileless malware is tricky. IT experts are essential to the process of protecting your hard-earned business data from any cyberattack. They know how to spot and defend against fileless malware attacks., Cybercriminals continue to find new ways to attack private and business data. SMBs don’t have the time or budget for a full-time IT department, so employing managed IT experts to provide risk analysis, assess your cyber vulnerability and help you design the best layers of protection for your business data limits the risk.

Q: How can businesses prevent being infected by fileless malware?

A: Preventing fileless malware involves a multi-layered security approach. Companies should disable unnecessary scripting tools, enforce application safelisting, regularly patch software to close known vulnerabilities and train users to recognize phishing attempts. Using advanced endpoint protection with behavior-based detection and limiting user privileges can also greatly reduce the risk of a successful fileless attack.

What’s the Best Method to Protect Against Fileless Malware?

Fileless malware removal relies on fileless malware detection, and both operations are best handled by IT security firms that specialize in preventing cyber threats of all kinds. They work with small and midsized businesses to provide employee cyber risk training and establish cybersecurity best practices to help ensure your confidential employee and client/patient data is secure. Connect with us if you are in the greater New York City area, or ask your IT provider for a referral to a professional cybersecurity company. Proactive steps help reduce the risk of a costly and time-consuming attack and help make recovery possible.