Solving ransomware

We’re back in Baltimore. Unfortunately not to relive Arjun’s favourite pithy one-liners from The Wire, but to talk about something from the non-fiction genre: Ransomware.

In just a few years, ransomware has gone from nothing to a multi-billion dollar industry. And it continues to grow. It’s little wonder that law enforcement are quietly holding crises summits to ask for help.

In May of this year, the City of Baltimore was hit with a ransomware attack. The ransomware used was called RobbinHood and it encrypted an estimated 10,000 networked computers. Email systems and payment platforms were taken offline. Baltimore’s property market also took a hit as people were unable to complete real estate sales.

One click away

Like most public sector technology environments, there appears to have been a mix of old and new systems on the City of Baltimore networks. Precisely because they are old, aging systems are typically unable to be “patched” or updated for known security threats, making them vulnerable.

But getting funding to replace or update computing systems is difficult, especially when you are competing with critical services like police, fire and hospitals.

Given the hard reality that many large networks will have a high volume of outdated, and therefore vulnerable, systems that are only one mouse click away from becoming infected, should we not focus more on preventing malware from propagating?

Trust

Most global corporate networks operate using a trust principal. If you are part of the same domain or group of companies you are trusted to connect to each other’s network. This has obvious benefits, but it also brings a number of risks when we consider threats like ransomware.

Strategies

There are many strategies to mitigate the risk of a ransomware outbreak. Back up your files, patch your computers and avoid opening suspicious links or attachments are commonly advised. At elevenM, we recommend these strategies, however we also work closely with our clients on an often overlooked piece of the puzzle, Active Directory. The theory being: if your network cannot be used to spread malware, your exposure to ransomware is significantly reduced.

Monitoring Active Directory for threats

To understand this in more detail, let’s go back to Baltimore. According to reports, the Baltimore attack came through a breach of the City’s Domain Controller, a key piece of the Active Directory infrastructure. This was then used to deliver ransomware to 10,000 machines. What if Balitmore’s Active Directory had been integrated with security tools that allowed it to monitor, detect, and contain ransomware instead of being used to propagate it?

Working with our clients’ and Active Director specific tools we have been able to separate and monitor Active Directory based threat indicators including:

  • Lateral movement restriction
  • Obsolete systems
  • Brute force detection
  • Anonymous users behaviour

All the pieces of the puzzle

In mitigating cyber threats, defence teams today have access to many tools and strategies. Often, there emerges a promised silver bullet to a particular threat. But the truth is that most threats will require a layered defence, involving multiple controls and core knowledge of common IT infrastructure (like Active Directory). Or to put it again in the language of the streets of Baltimore: “All the pieces matter“.

Want to hear more? Drop us a line at hello@elevenM.com