Hunting Residuals: The Fall of 'First VPN' and 25 Ransomware Crews
Just saw the briefing on the "First VPN" dismantling. It’s fascinating to see law enforcement (specifically French and Dutch authorities) take down a service provider specifically because it was a sanctuary for 25+ ransomware groups. We often talk about Tor nodes, but commercial criminal VPNs are a different beast—they offer higher bandwidth for scanning and exfiltration.
With the infrastructure seized, we're likely seeing a massive drop-off in specific scanning activities originating from their IP space. However, the real work for us is determining if any of our internal endpoints were inadvertently communicating with these nodes via installed malware or reverse shells.
I've started compiling the indicators from the Europol reports. If you are using Sentinel or a SIEM with KQL support, I highly recommend running a retrospective hunt for any connections to the known ASNs associated with this operation.
Here is a basic query to hunt for connections to the identified subnet ranges (replace with the specific IOCs from the official report):
DeviceNetworkEvents
| where Timestamp > ago(30d)
| where RemoteIP has_any ("45.142.212.", "185.156.46.")
| extend FullURL = strcat(URL, "?", tostring(RequestQuery))
| summarize count(), min(Timestamp), max(Timestamp) by DeviceName, RemoteIP, RemotePort, InitiatingProcessFileName
| order by count_ desc
Additionally, check your firewall logs for consistent high-volume traffic to these endpoints that abruptly stopped around the time of the takedown.
How is everyone else handling the fallout? Are you seeing any C2 beacons attempting to failover to backup infrastructure now that their primary VPN tunnel is dead?
Solid query, thanks for sharing. We noticed an immediate spike in 'Connection Timed Out' errors on our proxy logs right when the news broke. It looks like several dormant payloads tried to phone home and failed. We're pivoting to look for the specific JA3 fingerprints associated with First VPN's OpenVPN configs to see if we can spot any initial infection vectors that we missed.
This is a massive OpSec failure for the threat actors. Centralizing your C2 infrastructure through a known 'criminal' VPN is asking for a single point of failure. From a defensive perspective, this is a win, but I expect many of these groups will pivot to residential proxy services (like those millions of compromised IoT devices) to hide their traffic better. We've already updated our blocklists to include the new IP ranges released today.
The dismantling offers a rare opportunity for retrospective hunting. Now that the IP ranges associated with 'First VPN' are public, we can pivot back to historical logs to see if our infrastructure was targeted by these groups during the peak of their operations. It’s worth checking for successful outbound connections to those ranges, as it may indicate where C2 was successfully established prior to the seizure.
CommonSecurityLog
| where DestinationIP in ("")
| summarize count() by SourceIP, DestinationIP, Application
| order by count_ desc
Agreed, Eve. While retrospective checks are vital, we should also prepare for the pivot. Actors displaced from 'First VPN' might temporarily expose their real infrastructure or switch to residential proxies. I recommend tracking unusual User-Agent strings alongside the leaked IP ranges to catch residuals before they adapt.
Here’s a quick KQL snippet to hunt for specific successful connections in your network traffic logs:
DeviceNetworkEvents
| where RemoteIP in ("", "")
| where ActionType == "ConnectionAllowed"
| summarize count() by DeviceName, RemoteIP
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