Ransomware tries to slip unnoticed past security controls by abusing trusted and legitimate processes, and then harnesses internal systems to encrypt the maximum number of files and disable backup and recovery processes before an IT security team catches up, according to a new Sophos report.
Main modes of distribution for the major ransomware families
Ransomware is typically distributed in one of three ways: as a cryptoworm, which replicates itself rapidly to other computers for maximum impact (for example, WannaCry); as ransomware-as-a-service (RaaS), sold on the dark web as a distribution kit (for example, Sodinokibi); or by means of an automated active adversary attack, where attackers manually deploy the ransomware following an automated scan of networks for systems with weak protection.
Cryptographic code signing ransomware
Cryptographic code signing ransomware with a bought or stolen legitimate digital certificate in an attempt to convince some security software the code is trustworthy and doesn’t need analysis.
Privilege escalation using readily available exploits, like EternalBlue, to elevate access privileges. This allows the attacker to install programs such as remote access tools (RATs), and to view, change or delete data, create new accounts with full user rights, and disable security software.
Lateral movement and hunting across the network
Within an hour, attackers can create a script to copy and execute the ransomware on networked endpoints and servers.