Reignite your firewall to block ransomware

Reignite your firewall to block ransomware

Wana Tun

As cyberthreats continue to evolve rapidly, it is important for firewalls to be upgraded to protect against these threats.

Today, even in the most diligent organisations, there is usually a gap between the discovery of a vulnerability and the patching deployed, which can put the company at risk of a security lapse. This is why a next-generation firewall is essential to provide enterprises with a strong first line of defence against advanced threats.

In all next-generation firewalls, there is a critical security component known as Intrusion Prevention System (IPS), which performs deep packet inspection of network traffic to identify and block exploits before they reach a target host. In addition, a next-generation firewall also includes an essential security layer known as cloud-based sandboxing technology, which detects weaponised documents that lurk in common files like Microsoft Office documents and PDFs. It identifies suspicious files at the gateway and sends them to a safe sandboxing infrastructure in the cloud to detonate active content and monitor the behaviour over time.

Having said this, it is important to keep in mind that IPS and sandboxing are only effective against traffic that is moving across the firewall. Hence, there are some best practices to pursue in order to prevent the spread of worm-like attacks on the network.

Recommended best practices:

  • Ensure you have the right protection, including a modern, high-performance next-generation firewall IPS engine and sandboxing solution
  • Do thoroughly review the network and eliminate non-essential open ports accessible from outside, as open service ports are susceptible to attack, and a potential avenue for spreading worms. Therefore, where possible, it is recommended to use VPN to access resources on the internal network from outside
  • Apply sandboxing to web and email traffic to ensure all suspicious files coming through web downloads and email attachments are being analysed for malicious behaviour before they get into your network
  • Minimise the risk of lateral movement within the network by segmenting local area networks (LANs) into smaller, isolated zones or virtual local area networks (VLANs) that are secured and connected together by the firewall. Also, apply suitable IPS policies to the rules governing the traffic across the LAN to prevent exploits, worms and bots from spreading between LAN segments.
  • Automatically isolate infected systems. When an infection hits, it is vital that your security solution quickly identifies compromised systems and isolate them until they can be cleaned up, either automatically or through manual intervention.

As ransomware, botnets, and other advanced attacks are capable of spreading through the entire IT infrastructure, it is crucial for the firewall and the endpoint to communicate and share meaningful information about suspicious and confirmed bad behaviour.

Although this was not possible in the past, today, through the Sophos Synchronised Security approach, the endpoint and network can act as one integrated system to communicate information in real-time. This means enterprises can prevent, detect, investigate and remediate threats easily with minimal effort. In the past, this type of discovery and incident response would usually take weeks or months but is now reduced to seconds with synchronised security.

For organisations that do not have the luxury of extensive in-house security teams, the synchronised security approach can help bolster productivity while streamlining security operations and IT security management. As it delivers better protection and manageability, organisations of any size can also stay ahead of coordinated and sophisticated attacks.

Wana Tun is Global Solution Engineer, Sophos