Ransomware attacks in 2020 were conducted at twice the rate of the previous year, with many organizations falling victim and having to pay large ransoms to recover their data or risk sensitive information being published or sold to cybercriminal organizations.
At the start of 2020, data exfiltration prior to the deployment of ransomware was still only being conducted by a small number of ransomware gangs, but that soon changed as the year progressed. By the end of the year, at least 17 cybercriminal gangs were using this double extortion tactic and were stealing sensitive data prior to encrypting files. Faced with the threat of publication of sensitive data, many attacked organizations felt they had little alternative other than to pay the ransom demand.
The extent of ransomware attacks in 2020 has been highlighted by various studies by cybersecurity researchers over the past few weeks. Chainalysis recently released a report that suggests more than $350 million has been paid to cybercriminals in 2020 alone, based on an analysis of the transactions to blockchain addresses known to be used by ransomware threat groups. Of course, that figure is likely to be far lower than the true total, as many companies do not disclose that they have suffered ransomware attacks. To put that figure into perspective, a similar analysis in 2019 estimated the losses to be around $90 million. Those figures are for ransom payments alone, not the cost of resolving attacks, which would be several orders of magnitude higher.
The increase in attacks can be partly attributed to the change in working practices due to the pandemic. Many companies switched from office-based working to a distributed remote workforce to prevent the spread of COVID-19 and keep their employees protected. The rapid change involved hastily implementing remote access solutions to support those workers which introduced vulnerabilities that were readily exploited by ransomware gangs.
Most Ransomware Attacks Now Start with Phishing
Throughout 2020, phishing was commonly used as a way to gain access to corporate networks, accounting for between 25% and 30% of all ransomware attacks, but new data released by the ransomware attack remediation firm Coveware shows the attack methods changed in the last quarter of 2020. As companies and organizations addressed vulnerabilities in remote access solutions and VPNs and improved their defenses, phishing became the most common attack method. Coveware’s analysis shows that in the final quarter of 2020, more than 50% of ransomware attacks started with a phishing email.
Ransomware can be delivered directly through phishing emails, although it is more common to use intermediary malware. The most commonly used malware variants for distributing ransomware are Trojans such as Emotet and TrickBot, both of which are extensively delivered via phishing emails. These malware variants are also capable of self-propagating and spreading to other devices on the network.
Access to compromised devices is then sold to ransomware gangs, who access the devices, steal sensitive data, then deploy their ransomware payload. The Emotet botnet played a large role in ransomware attacks in 2020, and while it has now been disrupted following a joint law enforcement operation, other malware variants are certain to take its place.
The same report also highlighted the nature of businesses attacked with ransomware. Far from the gangs targeting large enterprises with deep pockets, most attacks are on small- to medium-sized businesses with under 250 employees. 30.2% of attacks were on businesses with between 11 and 100 employees, with 35.7% on businesses with 101 to 1,000 employees. Healthcare organizations, professional services firms, and financial services companies have all been targeted and commonly fall victim to attacks, although no sector is immune.
70% of ransomware attacks now involve data theft prior to encryption, so even if backups exist and can be used to restore data, it may not be possible to avoid paying the ransom. There is also a growing trend for data to be permanently deleted, which leaves businesses with no way of recovering data after a ransomware attack.
Steps to Take to Block Ransomware Attacks
What all businesses and organizations need to do is to make it as hard as possible for the attacks to succeed. While there is no single solution for blocking ransomware attacks, there are measures that can be taken that make it much harder for the attacks to succeed.
With most ransomware attacks now starting with a phishing email, an advanced email security solution is a must. By deploying best-of-breed solutions such as SpamTitan to proactively protect the Office365 environment it will be much easier to block threats than simply relying on Office 365 anti-spam protections, which are commonly bypassed to deliver Trojans and ransomware.
A web filtering solution can provide protection against ransomware delivered over the internet, including via links sent in phishing emails. Multi-factor authentication should be implemented for email accounts and cloud apps, employees should be trained how to identify threats, and monitoring systems should be implemented to allow attacks in progress to be detected and mitigated before ransomware is deployed.