Cymulate’s July 2022 Cyberattacks Wrap-up
July 2022 saw a range of ransomware attacks. Existing and new ransomware groups include LockBit, Hive, Lilith, RedAlert (aka N13V), and SMBs with H0lyGh0st ransomware.
DEV-0530
For example, one threat actor, also known as DEV-0530, used a dark website to interact with their victims. The group used the following methodology:- First, all files were encrypted on the target device with the file extension .h0lyenc.
- A sample of the encrypted files was sent to the victim as proof.
- Payment between 1.2 and 5 bitcoin was demanded in exchange for restoring access to the encrypted files.
- The pressure was applied on victims to pay up or risk having their information published on social media.
- On their dark web portal, the threat actors claimed to "close the gap between the rich and poor" and "help the poor and starving people."
MedusaLocker
Also, in July 2022, MedusaLocker, typical ransomware that encrypts victims' data and demands ransom for the decryption key, was active. The threat actors behind the ransomware attacks use a Ransomware-as-a-Service (RaaS) business model. The developer of MedusaLocker provided other threat actors with the ransomware in exchange for a share of the ransom payments. The split seems to be 55%-60% for the treat actors who receive the payment and 40%-45% for the developer of MedusaLocker. The MedusaLocker attacks followed a well-known pattern:- The threat actors used phishing and spam emails to deliver the ransomware to their victims.
- Sometimes, the threat actors abused vulnerable Remote Desktop Protocol (RDP) configurations.
- The ransomware used a batch file to execute the PowerShell script invoke-ReflectivePEInjection.
- This script propagated MedusaLocker throughout the network by editing the EnableLinkedConnections value within the infected machine's registry.
- This allowed the infected machine to detect attached hosts and networks via the Internet Control Message Protocol (ICMP)
- Shared storage was detected via the Server Message Block (SMB) Protocol.
- MedusaLocker then restarted the LanmanWorkstation service to have the registry edits take effect.
- The ransomware then killed security, accounting, and forensic software processes.
- The machine was restarted in safe mode to avoid detection by security software.
- The victim's data was encrypted with the AES-256 encryption algorithm.
- The resulting key was then encrypted with an RSA-2048 public key.
- Persistence was established by copying an executable (svhost.exe or svhostt.exe) to the %APPDATA%\Roaming directory and scheduling a task to run the ransomware every 15 minutes.
- Standard recovery techniques were prevented by deleting local backups, disabling startup recovery options, and deleting shadow copies.
- The MedusaLocker threat actors left a ransom note with communication instructions in every folder containing an encrypted file.
- This note instructed the victims on how to make ransomware payments to a specific Bitcoin wallet address.
- The demanded amount seemed to be tailored to the victim's perceived financial status.