There has been much media coverage of ransomware over the past several months. The healthcare industry has been in this spotlight most recently, but financial services is certainly not immune to this threat. Back in mid-2014, a U.S. brokerage house fell victim to CryptoWall, which both encrypted and exfiltrated data from that institution. Although there have not been many public disclosures of ransomware incidents at financial institutions as of late, CryptoWall ransomware was one of the top 3 threats to the industry in both 2014 and 2015 based on research by Unit 42, the Palo Alto Networks threat intelligence team. In late 2015, the U.S. Federal Financial Institutions Examination Council (FFIEC) and the Financial Services Sector Coordinating Council (FSSCC) issued separate alerts on cyber extortion and destructive malware, respectively. So it’s clear that the financial services industry needs to be prepared to address such malicious attacks.
Ransomware is essentially malware that encrypts data on personal computers and network drives until a payment made to the perpetrator. The ransom demanded is usually a small monetary amount to increase the likelihood of payment. Ultimately, this may boil down to a business decision over the time and effort required to restore files from back-ups versus the cost of the ransom to obtain the decryption key from the attacker. For more details about the evolution of ransomware, please see the new report on ransomware trends from Unit 42.
To protect themselves from the impact of ransomware, financial institutions should conduct regular back-ups of data on PCs, shared drives, and any other storage systems. Moreover, the data on the back-up system needs to be verified to ensure there are no surprises when restorations are warranted. This should already be a recurring practice as part of business continuity plans, but it’s worthwhile to validate this since viable back-ups are integral to any ransomware remediation actions.
Preventing infection by ransomware is an even better course of action. It eliminates lost productivity and impact to business operations, as well as the overhead associated with removing the malware and restoring the encrypted data files. By establishing defenses at multiple layers of the network, the following steps will significantly improve an institution’s ability to prevent ransomware attacks from being widely successful.
- Scan and block suspicious files (e.g., portable executables) in all inbound e-mail or web-browsing sessions
- Prevent the ingress of malware by using intrusion prevention systems (IPS) for known threats and sandbox analysis for zero-day threats
- Block outbound traffic to malicious URLs or sites, which may be part of the attack lifecycle for ransomware
- Prevent exploits and malware execution on PCs and servers with endpoint protection capabilities above and beyond anti-virus and host IPS
- Contain any threats by segmenting the internal network to limit lateral movement and to minimize the fault domain
The Palo Alto Networks Next-Generation Security Platform offers a multi-layered approach to prevent ransomware from infecting financial services institutions. These capabilities can be part of an overall defense plan against ransomware. To learn more about how this works, visit our Financial Services resource page.