Koolova Ransomware Decrypts For Free If You Read Two Articles About Ransomware

An anonymous reader quotes a report from BleepingComputer: We have a new in-development variant of the Koolova Ransomware that will decrypt your files for free if you educate yourself about ransomware by reading two articles. Discovered by security researcher Michael Gillespie, this in-development ransomware is not ready for prime time. In fact, I had to mess with it a bit and setup a local http server to even get it to display the ransom screen. In its functional state, Koolova will encrypt a victim's files and then display a screen similar to the Jigsaw Ransomware where the text is slowly shown on the screen. This text will tell the victim that they must read two articles before they can get a decryption key. It then tells you that if you are too lazy to read two articles before the countdown gets to zero, like Jigsaw, it will delete the encrypted files. This is not an idle threat as it actually does delete the files. The articles that Koolova wants you to read are an article from Google Security Blog called Stay safe while browsing and BleepingComputer's very own Jigsaw Ransomware Decrypted: Will delete your files until you pay the Ransom article. Once you read both articles, the Decripta i Miei File, or Decrypt My Files, button becomes available. Once you click on this button, Koolova will connect to the Command and Control server and retrieve the victim's decryption key. It will then display it in a message box labeled "Nice Jigsaw," in reference to the Jigsaw Ransomware, that displays your decryption key. A victim will then be able to take that key and enter it into the key field in order to decrypt files.

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iptables -A INPUT -j DROP && iptables -A OUTPUT -j DROP

Reset-ADAccountPassword -Identity krbtgt

winpmem.exe -o memdump.raw / dd if=/dev/fmem of=mem.raw

Verify WORM-Storage Lock status

title: Detect Exploitation - Koolova Ransomware Decrypts For Free If You Read Two Articles About Ransomware
id: 4c0f6f37-6c90-4e8b-8737-3a7061e9a545
status: experimental
description: Automatisch generierte SIEM-Erkennungsregel basierend auf CTI Intelligence
references:
  - https://tsecurity.de/
author: iShareStuff CTI Automated Detection Engine
date: 2026-09-26
logsource:
  category: network_connection
  product: any
detection:
  selection:
      CommandLine|contains:
        - 'exploit'
  condition: selection
falsepositives:
  - Legitime administrative Zugriffe oder Penetrationstests
level: high
tags:
  - attack.initial_access
  - attack.t1486

rule CTI_Threat_Indicator {
    meta:
        author = "iShareStuff CTI Automated Detection Engine"
        date = "2026-09-26"
        description = "YARA Signature for "
    strings:
        $str = "Koolova Ransomware Decrypts Fo" ascii wide
    condition:
        any of them
}

index=security sourcetype IN ("cisco:asa", "pan:traffic", "zeek_conn", "suricata", "WinEventLog:Security")
("Koolova Ransomware Decrypts For Free If ")
| stats count earliest(_time) as first_seen latest(_time) as last_seen by src_ip, dest_ip, dest_host, signature
| eval first_seen=strftime(first_seen, "%Y-%m-%d %H:%M:%S"), last_seen=strftime(last_seen, "%Y-%m-%d %H:%M:%S")
| sort - count

message: "*Koolova Ransomware Decrypts For Free If *"

CommonSecurityLog
| where Message has "Koolova Ransomware Decrypts For Free If "
| summarize EventCount = count(), FirstSeen = min(TimeGenerated), LastSeen = max(TimeGenerated) by SourceIP, DestinationIP, DestinationPort, Activity
| extend DetectionRule = "iShareStuff-CTI-Compiled"
| sort by EventCount desc