Machine learning could help companies react faster to ransomware

Exabeam uses machine learning, behavior analytics to help companies contain ransomware infections

File-encrypting ransomware programs have become one of the biggest threats to corporate networks worldwide and are constantly evolving by adding increasingly sophisticated detection-evasion and propagation techniques.

In a world where any self-respecting malware author makes sure that his creations bypass antivirus detection before releasing them, enterprise security teams are forced to focus on improving their response times to infections rather than trying to prevent them all, which is likely to be a losing game.

Exabeam, a provider of user and entity behavior analytics, believes that machine-learning algorithms can significantly improve ransomware detection and reaction time, preventing such programs from spreading inside the network and affecting a larger number of systems.

Because the decryption price asked by ransomware authors is calculated per system, isolating affected computers as soon as possible is critical. Only last week the University of Calgary announced that it paid 20,000 Canadian dollars (around US$15,600) to ransomware authors to get the decryption keys for multiple systems.

Exabeam's Analytics for Ransomware, a new product that was announced today, uses the company's existing behavior analytics technology to detect ransomware infections shortly after they occur.

The product uses data from a company's existing logs to build behavior profiles for computers and users. This allows it to detect previously unknown ransomware without pre-existing detection signatures by analyzing anomalies in the file and document behavior of employees.

To avoid false positive detections, the technology flags incidents as ransomware when the combined risk score of multiple suspicious activities that could indicate this type of threat reaches a certain threshold.

Exabeam's security research team is helping train the product in a laboratory by executing a very large number of ransomware samples on test computers and letting it observe their behavior in order to build threat models.

ransomware detection exabeam behaviour machine learning Exabeam

Exabeam builds a threat score based on behavioural anomalies.

The product does not have blocking capabilities itself and is intended to be used by a company's security analysts to quickly spot and respond to security incidents. It is available as an add-on to the company's larger analytics platform, which can already detect violations of internal company security policies.

Even though there's no built-in threat neutralization functionality, the platform can integrate with other security tools and allow analysts to create administrative scripts that are executed automatically when an incident is detected -- for example, to immediately isolate an infected computer from the rest of the network.

Ransomware is typically distributed through drive-by download attacks and phishing emails, which means that computers are affected one-by-one, based on users' actions. However, in a corporate setting, ransomware can easily spread beyond a single computer by affecting files on document-sharing servers and other collaboration services used by employees.

Recently, some ransomware programs even gained worm-like, self-spreading capabilities. Once such threat is called ZCrypt and it copies itself to external USB drives, from where it's executed via rogue autorun.inf files.

By running a very large number of ransomware samples in a laboratory environment, the Exabeam researchers have also observed some interesting trends: for example, a recent increase in the ransom price.

"Two or three months ago most ransom values were between 0.4 and 1 bitcoin," said Barry Shteiman, the head of threat research at Exabeam. "That changed over the past month, the price now being between 2 and 5 bitcoins."

This could also be driven by the fact that many ransomware authors are now focused on targeting businesses, and companies are willing and able to pay more than consumers in order to recover critical business files.

Another interesting observation is that no new ransomware installer remains functional for more than a day.

This indicates that "ransomware campaigns are changing every day," Shteiman said. "It's like their creators work in DevOps mode, releasing new code to their spamming partners every day."

Join the CSO newsletter!

Error: Please check your email address.

More about

Show Comments

Featured Whitepapers

Editor's Recommendations

Solution Centres

Stories by Lucian Constantin

Latest Videos

  • 150x50

    CSO Webinar: Will your data protection strategy be enough when disaster strikes?

    Speakers: - Paul O’Connor, Engagement leader - Performance Audit Group, Victorian Auditor-General’s Office (VAGO) - Nigel Phair, Managing Director, Centre for Internet Safety - Joshua Stenhouse, Technical Evangelist, Zerto - Anthony Caruana, CSO MC & Moderator

    Play Video

  • 150x50

    CSO Webinar: The Human Factor - Your people are your biggest security weakness

    ​Speakers: David Lacey, Researcher and former CISO Royal Mail David Turner - Global Risk Management Expert Mark Guntrip - Group Manager, Email Protection, Proofpoint

    Play Video

  • 150x50

    CSO Webinar: Current ransomware defences are failing – but machine learning can drive a more proactive solution

    Speakers • Ty Miller, Director, Threat Intelligence • Mark Gregory, Leader, Network Engineering Research Group, RMIT • Jeff Lanza, Retired FBI Agent (USA) • Andy Solterbeck, VP Asia Pacific, Cylance • David Braue, CSO MC/Moderator What to expect: ​Hear from industry experts on the local and global ransomware threat landscape. Explore a new approach to dealing with ransomware using machine-learning techniques and by thinking about the problem in a fundamentally different way. Apply techniques for gathering insight into ransomware behaviour and find out what elements must go into a truly effective ransomware defence. Get a first-hand look at how ransomware actually works in practice, and how machine-learning techniques can pick up on its activities long before your employees do.

    Play Video

  • 150x50

    CSO Webinar: Get real about metadata to avoid a false sense of security

    Speakers: • Anthony Caruana – CSO MC and moderator • Ian Farquhar, Worldwide Virtual Security Team Lead, Gigamon • John Lindsay, Former CTO, iiNet • Skeeve Stevens, Futurist, Future Sumo • David Vaile - Vice chair of APF, Co-Convenor of the Cyberspace Law And Policy Community, UNSW Law Faculty This webinar covers: - A 101 on metadata - what it is and how to use it - Insight into a typical attack, what happens and what we would find when looking into the metadata - How to collect metadata, use this to detect attacks and get greater insight into how you can use this to protect your organisation - Learn how much raw data and metadata to retain and how long for - Get a reality check on how you're using your metadata and if this is enough to secure your organisation

    Play Video

  • 150x50

    CSO Webinar: How banking trojans work and how you can stop them

    CSO Webinar: How banking trojans work and how you can stop them Featuring: • John Baird, Director of Global Technology Production, Deutsche Bank • Samantha Macleod, GM Cyber Security, ME Bank • Sherrod DeGrippo, Director of Emerging Threats, Proofpoint (USA)

    Play Video

More videos

Blog Posts

Market Place