Ransomware Detection: Effective Strategies and Tools

In today’s environment, it may be impossible to avoid falling victim to a hacking attack altogether. The scale of criminal activity and the complex, constantly-evolving tactics used by ransomware groups means that even the best-prepared businesses cannot block every attack from infiltrating their networks.

Therefore, being able to detect ransomware and remove it from systems before it has a chance to do damage is essential. Without the ability to identify and respond to these attacks, firms are likely to end up facing huge bills. Expenses can range from ransomware payments to lost business, recovery costs, investigations and potential penalties from regulators.

For some businesses, the first indication that they have been infected with ransomware may be when they suddenly discover they can’t access critical data and a demand for payment arrives. By this time, it will be far too late. In such events, attacks will already have achieved their objective and caused considerable damage. This means firms will inevitably face significant downtime while they try to recover lost data and get operations up and running again.

If data has been exfiltrated as part of the attack, the challenges could be even greater. Once sensitive information is in the hands of hackers, there is very little that can be done. Even if a ransom is paid, there is no guarantee that cybercriminals will keep any promises to destroy stolen data.

According to figures from IBM, if the first disclosure of a breach comes from the attacker, the average cost to businesses is $5.53 million as of 2024. However, when a security team is able to identify a breach before this happens, the average cost drops to $4.55 million. 

Being able to identify and shut down a ransomware attack before it has a chance to exfiltrate data is therefore one of the most important security strategies for any business. The longer a hacker is able to move undetected within a network, the more data they will be able to exfiltrate and the harder it will be to recover.

Even before getting a ransom note, there may be a range of telltale signs that could indicate a system has been infected with ransomware. Knowing how to spot these could be the difference between successfully foiling an attack and facing a multi-million dollar bill. Look out for the below indicators that could be a sign of an attack in progress.

• Spikes in activity – Unusual changes within a network, such as increased traffic or a spike in disk activity, can indicate attackers are searching for data or attempting to exfiltrate information.
• Poor system performance – Many ransomware attacks will require significant system resources to find, encrypt and exfiltrate data, which can have a negative impact on the overall performance of a device.
• Creation of new user accounts – The appearance of new users without the approval of IT administrators could mean hackers are at work, especially if newly-created accounts have a high level of privilege.
• Disabled security tools – Many malware authors will include steps that aim to covertly disable security tools in order to evade detection, so if firms notice these defenses have been disabled without being instructed by IT teams, this should raise alarms.
• Unexpected file modifications – An increase in the number of files being renamed or having their extensions modified can be a key sign that an attack is underway. Discovering encrypted files should also be a major red flag.
• Popups/ransom notes  – The final stage of any ransomware attack is to notify victims, which often comes in the form of popups or splash screens on devices.  Unfortunately, by this time, it is often too late.

Spotting any of these signs through effective system monitoring means that firms must immediately activate their ransomware response and recovery plan. This includes isolating any potentially infected systems until a thorough investigation can be done in order to identify and remove any ransomware.

There are a range of methods that can be used to detect ransomware, but they all have one thing in common: comprehensive monitoring across an entire network. Knowing how the tools work is highly useful in creating a comprehensive strategy that provides the highest levels of protection.

Perhaps the most traditional way of detecting malware, this looks for telltale signatures contained within files, and is the way most antivirus software works. However, this approach does have limitations. For instance, it cannot detect zero-day vulnerabilities or fileless attacks, as these will not leave behind the essential traces that these solutions look for.

This technique focuses on the way ransomware interacts with files as it seeks out and encrypts them. These tools monitor systems for activity such as renaming, copying or replacing files and alerts security teams to suspicious behavior within the network.

Heuristic evaluation works by looking for commands and instructions within applications that would not normally be present in genuine programs. For example, it can detect behavior such as self-replicating files or attempts to remain within memory after rewriting files, which are common markers of viruses. However, like signature-based detection, these efforts rely on looking for known threat patterns, making it harder to spot novel types of attack.

These solutions work by monitoring traffic, both within the network and to destinations outside the perimeter, looking for unusual patterns. For instance, traffic going to unknown locations, or large volumes of transfers outside normal working hours may be flagged as suspicious. This is particularly important when it comes to preventing data exfiltration – a key component of dangerous double extortion ransomware attacks.

Many anti-ransomware techniques work by looking for unusual patterns of behavior. However, this may make them prone to issues such as false positives, which can result in legitimate activities being blocked, causing unnecessary disruption. To avoid this, and to provide more accurate detection of ransomware, many solutions are now incorporating artificial intelligence and machine learning technology, which can build up a more complete picture of what normal activities look like. This makes it easier to spot anomalies and ensures solutions are not relying on reactive signature-based methods.

There are a number of options for businesses when it comes to detecting ransomware. There’s no one silver bullet, so it’s vital that companies have a full range of tools in place, with different technologies needed for perimeter defenses, internal network monitoring and protecting endpoints.

For example, solutions such as email security operate as a first line of defense to block ransomware before it enters the network. With technology such as machine learning, this can help more accurately identify phishing attacks by recognizing unusual language or requests that aim to trick employees into handing over information or downloading malware-infected files.

One essential last line of defense is anti data exfiltration (ADX) technology. This plays a critical role in guarding against double extortion ransomware by preventing cybercriminals from stealing sensitive information, and is something which should be deployed across the network.

BlackFog’s ADX solution, for example, has been designed to be lightweight enough to sit on any endpoint and analyze traffic on-device. This enables it to respond faster to suspicious activity and block traffic automatically, without the need to wait for human intervention.

As well as technological solutions, there are a few best practices that businesses need to incorporate into their security strategy in order to improve their ransomware detection. These include:

• Employee training – Educating everyone in the company about how to spot phishing attempts and other social engineering techniques can help shut down ransomware attacks before they have a chance to get established on a network.
• Continuous monitoring – Ensuring that all activities across the network are constantly being monitored and logged helps spot ransomware in real-time. It also provides a full audit trail for later evaluation so that, in the event an incident does occur, there is a full record of what happened.
• Incident response planning – It’s vital to remember that ransomware detection is only the first step. Once an infection has been discovered, firms need a clear plan for how to respond. This means drafting a comprehensive strategy for this in advance that can be referred to during a ransomware incident, spelling out what must be done and who is responsible for which actions.  

It’s important to take on board any lessons from ransomware attacks, whether they were successful in encrypting or exfiltrating data or not. Understanding how the infection entered the system, what – if any – mistakes were made and where procedures and technologies need to be strengthened will be vital in protecting businesses in the future.