Ransomware remains an active threat for organizations into 2018. Last year, large scale attacks like NotPetya and WCry wreaked havoc, shutting systems and costing millions of dollars in recovery. To develop effective mitigation strategies, we need to closely analyze the ever-evolving ransomware landscape. In particular, we expect developments in four broad areas, namely: ransomware delivery mechanisms, lateral movement tools, service models, and payment mechanisms.
Ransomware Developments in 2018
1. Delivery mechanisms
Ransomware can be delivered by multiple vectors. To limit the need for initial user interaction, threat actors are using exposed internet facing infrastructure, like Remote Desktop Protocol (RDP) as an entry vector. This is partly due to availability, especially as RDP credentials or brute forcing tools are easily purchasable on criminal forums. However, there are also tactical and operational reasons for this: RDP allows machine access, meaning that threat actors can identify specific areas of valuable data or even move laterally across networks.
Figure 1: RDP brute forcing tool advertised for $4.25 on criminal marketplace
Other remote entry vectors that ransomware operators can target include Internet Information Services (IIS) or JBoss application servers.
Self-propagation mechanisms leverage the damaging impact of a single endpoint infection. Companies with locked down external networks may have flat internal networks, producing conditions for ransomware to self-propagate. Self-propagation is becoming popular among ransomware operators because:
- Tools like PsExec and Windows Management Instrumentation Command can use batch script files to automate lateral movement within networks
- Vulnerability exploits are available, for example SMB exploit “EternalBlue” used during WCry
- Malicious groups can demand larger extortion amounts with multiple infections, or produce a highly damaging attack like NotPetya
3. Ransomware as a service (RaaS)
Ransomware as a service (RaaS) models give threat actors without skills or resources the ability to deliver ransomware. Like other as a service models, users can sign up to platforms that provide backend infrastructure to manage operations. While RaaS is not new, the continued emergence of new variants shows the service remains in active development, and that a market still exists for it. This service model opens the ransomware marketplace to a wider variety of threat actors, while still remaining profitable for developers as they generally receive a percentage of each infection.
4. Payment mechanisms
Ransomware variants deployed in financially motivated attacks live and die by profit generation. Payment mechanisms are currently an area of weakness for ransomware developers as they are not often automated or scalable. Ransomware operators tend to rely on email or TOR sites with cryptocurrency payments, which likely reduces operational effectiveness. Some variants have fully automated payment system infrastructure, from infection to payment, and delivery of decryption keys; however, these are relatively limited. Large, self-propagating attacks to date had poorly implemented payment infrastructure – as seen with the WCry attack that only had three Bitcoin wallets to receive payment due to a bug in the malware’s code.
Building your Ransomware Playbook
Establishing a ransomware playbook can help preparation for an eventual attack. The playbook can be used to define specific roles and functions should the unwanted occur, allowing organizations to establish tactics for managing a ransomware infection, as well as strategies for dealing with the aftermath. An effective ransomware playbook:
- Requires a whole-of-business approach to planning. Ransomware affects multiple business areas and may result in large scale service disruption
- Plans responses to extortion demands and identifies “worst case” scenarios
- Shows an understanding of your playing field and adversaries. Threat intelligence can help to inform approaches to ransomware attacks
For more insight into the ransomware ecosystem, join our live webinar on “Emerging Ransomware Threats and How to Protect Your Data” being held on 15 March 2018. Hear from Digital Shadows’ analysts and the FBI Cyber Division’s leading ransomware investigator about the latest threats and vectors, as well as best practices for protecting you and your organization.