Threat Analysis Unit (TAU) Threat Intelligence Notification: CoronaVirus Ransomware

“CoronaVirus” Ransomware has been found distributed via a phishing website. The malicious website will distribute a trojan downloader which then leads to downloading additional malicious payloads: the Kpot InfoStealer and Coronavirus Ransomware.

“CoronaVirus” Ransomware will perform the deletion of volume shadow copies and overwrite the Master Boot Record (MBR) of the hard disk. It will also drop ransom notes named “CoronaVirus.txt” to the victim as shown in Figure 2.

Figure 1: Malware distribution

Figure 2: Screenshot of the ransom note

Details

  • Upon execution it will delete itself, then create a copy of itself to the %TEMP% directory with a randomly generated filename.
  • It will rename system C drive to “CoronaVirus”
  • It will modify the following registry key to display ransom note on screen during reboot and startup:
    • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager “BootExecute” autocheck autochk * {%TEMP%\”RansomNote”}
    • HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run {%TEMP%\CoronaVirus.txt}
  • It will perform the deletion of volume shadow copies with the following command:
    • “C:\Windows\system32\VSSADMIN.EXE” Delete Shadows /All /Quiet
    • “C:\Windows\system32\wbadmin.exe” delete backup -keepVersions:0 -quiet
    • “C:\Windows\system32\wbadmin.exe” delete systemstatebackup -keepVersions:0 -quiet

Behavioral Summary

The following is a screenshot of Cloud Enterprise EDR (CB ThreatHunter) process chart by “CoronaVirus” Ransomware.

In addition, VMware Carbon Black Cloud Endpoint Standard (CB Defense) will display the malware’s overall triggered TTPs.

Customer Protection

CoronaVirus Ransomware is blocked and detected by existing policies within VMware Carbon Black products. To learn more about further ransomware behavior, detection and protection capabilities within the Carbon Black suite of products against CoronaVirus ransomware, you may refer to the following blog post:

TAU-TIN – Ransomware Threats

MITRE ATT&CK TIDs

TID Tactics Technique
T1143 Defense Evasion Hidden Window
T1083 Discovery File and Directory Discovery
T1060 Persistence Registry Run Keys / Startup Folder
T1112 Defense Evasion Modify Registry
T1497 Defense Evasion,Discovery Virtualization/Sandbox Evasion
T1006 Defense Evasion File System Logical Offsets
T1067 Persistence Bootkit
T1490 Impact Inhibit System Recovery
Indicators of Compromise (IOCs)
Indicator Type Context
5987a6e42c3412086b7c9067dc25f1aaa659b2b123581899e9df92cb7907a3ed SHA256 Trojan Downloader
3299f07bc0711b3587fe8a1c6bf3ee6bcbc14cb775f64b28a61d72ebcb8968d3 SHA256 CoronaVirus Ransomware
a08db3b44c713a96fe07e0bfc440ca9cf2e3d152a5d13a70d6102c15004c4240 SHA256 Kpot InfoStealer
cb2b4cd74c7b57a12bd822a168e4e608 MD5 Trojan Downloader
ec517204fbcf7a980d137b116afa946d MD5 CoronaVirus Ransomware
99785ae0679d6d3e27de83af403c23b0 MD5 Kpot InfoStealer
wisecleaner[.]best URL Phishing website
trynda[.]xyz URL Trojan Downloader website