According to Crowdstrike, “Living off the land (LOTL) is a fileless malware or LOLbins cyberattack technique where the cybercriminal uses native, legitimate tools within the victim’s system to sustain and advance an attack.” Unlike conventional malware that relies on signature-based detection, LOTL attacks operate in the shadows, evading traditional security measures and leaving organizations vulnerable to prolonged, undetected intrusions.
Understanding the mechanics of LOTL attacks
At the heart of LOTL attacks lies exploiting legitimate, native tools within the target environment. Cybercriminals do not need to install any malicious code or scripts; instead, they manipulate existing system utilities, such as PowerShell, Windows Management Instrumentation (WMI), or the password-saving tool Mimikatz, to infiltrate, escalate privileges, and execute their malicious objectives. The fileless approach makes LOTL attacks remarkably difficult to detect, as they leave no traditional malware signatures or files behind.
Expert insight
José Toledo, a cybersecurity consultant at Google, specializes in assessments and developing cybersecurity programs, network security, and cloud security. With a strong background in enterprise networks and vulnerability management, Toledo has helped numerous organizations strengthen their defenses against changing cyber threats.
Toledo uses a vivid analogy to explain the nature of Living off the Land (LotL) attacks: “Imagine a burglar breaking into a house, not by bringing their own tools, but by using whatever they find in the garage — a hammer, a screwdriver, maybe even a ladder left leaning against the wall. This, in essence, is the core principle behind LotL attacks.”
He elaborates on how these attacks work: "Instead of relying on external malware or malicious code, attackers leverage legitimate tools and software already present on the victim’s system to achieve their objectives." The real challenge with LotL attacks, according to Toledo, is their ability to evade traditional security defenses. "By utilizing trusted system tools, these attacks often fly under the radar, blending in seamlessly with normal system activity. This makes detection incredibly challenging, as security solutions might struggle to distinguish between legitimate use and malicious intent."
Through this method, attackers can bypass conventional security measures, making LotL attacks both subtle and dangerous.
Gaining initial access
LOTL attackers employ a variety of techniques to gain their initial foothold in the target system. Exploit kits, which contain collections of exploits targeting known vulnerabilities, allow them to inject malicious code directly into memory without leaving any traces on the disk. Hijacked native tools, or ‘dual-use’ tools, provide a convenient cover for the adversary to carry out their activities, as these tools are often whitelisted and overlooked by security measures.
Establishing persistence and lateral movement
Once inside the target environment, LOTL attackers try to maintain their presence and broaden their access. They use registry resident malware, which hides malicious code in the Windows registry to ensure continued access even after the system restarts. Memory-only malware runs solely in memory, avoiding detection by conventional security tools. Fileless ransomware encrypts files without leaving any malicious code on the disk, showcasing the advanced nature of LOTL attacks.
The allure of LOTL attacks
The growing popularity of LOTL attacks can be attributed to several factors. Firstly, these attacks are highly effective, as they bypass signature-based detection and often go unnoticed for extended periods. Secondly, the use of legitimate tools provides the attackers with a perfect cover, as their activities can be easily overlooked or dismissed as normal system operations. Additionally, the lack of files or signatures makes it challenging to attribute these attacks, allowing cybercriminals to reuse their tactics with impunity.
Detecting and preventing LOTL attacks
To effectively address LOTL attacks, it’s necessary to employ methods beyond conventional security measures. Focusing on indicators of attack (IOAs) — which analyze the intent and context of actions rather than specific signatures — helps identify these subtle threats. Additionally, managed threat-hunting services that actively search for signs of compromise can effectively detect and interrupt LOTL attacks before they escalate.
Enhancing visibility and control
Organizations need a clear understanding of their asset inventory and applications to enhance visibility and control. Keeping an updated asset inventory and optimizing application management aids in identifying and addressing vulnerabilities, which reduces the attack surface exposed to exploit kits and hijacked tools.
Account monitoring and access control
Monitoring user accounts and access privileges assists in defending against LOTL attacks. Implementing rigorous account monitoring and management controls helps detect and prevent unauthorized activities, reducing the risk of stolen credentials being used for fileless attacks.
Compromise assessment and recovery
When a LOTL attack is suspected, a swift compromise assessment is necessary. Reviewing past events and spotting indicators of ongoing or previous intrusions can help the security team contain the damage, recover affected systems, and strengthen the network to prevent future attacks.
In the news
To combat the use of living off the land (LOTL) techniques, the National Security Agency (NSA) has released a guide on event logging. The publication offers guidance on logging and detecting threats across cloud services, enterprise networks, mobile devices, and operational technology (OT) networks, ensuring the uninterrupted operation of systems. It discusses the challenges posed by advanced persistent threat actors (APTs) who use LOTL methods to evade detection. The guide is designed for senior IT and OT leaders, network administrators, and critical infrastructure providers.
FAQs
What is a living off the land (LOTL) attack and how does it relate to healthcare security?
A living off the land (LOTL) attack involves cybercriminals using legitimate software and tools already present in a system to carry out malicious activities, rather than relying on external malware. In healthcare, LOTL attacks exploit trusted applications to gain unauthorized access to systems, manipulate data, or maintain persistence, making them harder to detect and posing a threat to the security of electronic protected health information (ePHI).
Why are LOTL attacks particularly dangerous for healthcare organizations?
LOTL attacks are particularly dangerous because they exploit trusted, legitimate tools that are already part of the system’s normal operations, making detection difficult. In healthcare, such attacks can lead to unauthorized access to ePHI, manipulation of medical records, and disruptions in healthcare services, all of which can result in HIPAA violations and severe repercussions for patient privacy and safety.
What are the potential risks associated with LOTL attacks under HIPAA?
- Data breaches: Attackers can use trusted tools to access and exfiltrate ePHI without triggering traditional security alarms.
- Data manipulation: Legitimate software may be used to alter medical records or other sensitive data, potentially leading to incorrect treatment or diagnoses.
- Non-compliance penalties: The use of LOTL tactics can result in unnoticed security breaches, leading to HIPAA violations and significant legal and financial penalties.
- Operational disruptions: LOTL attacks can undermine the integrity of healthcare systems, causing disruptions that affect patient care and administrative processes.
- Reputational damage: Successful LOTL attacks can erode trust in the healthcare organization, damaging its reputation and patient relationships.
Learn more: HIPAA Compliant Email: The Definitive Guide
Farah Amod
