UNC2814 (GRIDTIDE) Takedown: Assessing Residual Risk in Telco Infra
Saw the update this morning regarding Google's disruption of the UNC2814 (GRIDTIDE) operation. Breaching 53 organizations across 42 countries—specifically targeting government and telco sectors—is a massive scope. Given the actor's history of espionage, the disruption of C2 infrastructure is a significant win, but it doesn't automatically purge the implants sitting on endpoints.
For those of you in the targeted sectors, are you seeing any residual traffic attempting to phone home to dead domains? We're specifically hunting for webshells that might have been dropped prior to the takedown. The report mentioned they've been elusive, so persistence mechanisms are likely sophisticated.
We've started rolling out some new detection logic for webshell activity in IIS/Apache logs, focusing on suspicious user-agents and header anomalies. Here is a quick KQL snippet we're using to triage potential backdoors in our environment:
DeviceNetworkEvents
| where RemoteIP in (external_IOCs_list)
| where InitiatingProcessFileName has_any ("w3wp.exe", "java", "nginx")
| project Timestamp, DeviceName, RemoteUrl, InitiatingProcessCommandLine
| order by Timestamp desc
Additionally, we are scanning for suspicious registry modifications often used for persistence:
Get-ItemProperty -Path "HKLM:\Software\Microsoft\Windows\CurrentVersion\Run" | Where-Object {$_.PSObject.Properties.Name -match "^[a-zA-Z]{4,8}\.dll$"}
How are you handling the incident response side of things? Are you assuming compromise or relying on proactive hunting to find nothing?
We're assuming compromise in our telecom division. The KQL is solid, but we found a lot of noise from w3wp.exe connecting to external CDNs. Make sure to whitelist your known legit IPs first or you'll drown in alerts. We're pivoting to looking for anomalous outbound SMB traffic, as that was a hallmark of their lateral movement in similar campaigns.
Interesting takedown. I've seen similar groups abuse web-facing management interfaces—often unpatched VPNs or mail servers. If they breached telcos, they likely exploited edge services or leveraged valid credentials. Did the report mention specific CVEs? I'm curious if they re-used known exploits like the Exchange ones or something novel. Always check for accounts created just outside the breach window.
As an MSP, this is a nightmare fuel. We don't manage telcos, but the supply chain risk is real if our vendors use compromised providers. I'm pushing out a forced audit of all remote access tools. Anyone using open-source IOC frameworks to automate the ingestion of the new indicators released by Google?
Solid advice on whitelisting. To catch those residual callbacks specifically, pivot to your DNS logs. With C2 dead, implants will often generate massive spikes in NXDOMAIN responses as they try to resolve their domains. This is often a cleaner signal than netflow if you're drowning in w3wp.exe noise. Here’s a quick KQL query to spot those failed resolution attempts:
kusto DnsEvents
| where ResponseCode == 3 // NXDOMAIN
| summarize count() by Bin(Timestamp, 5m), Subnet
| where count_ > 100
Check if those subnets align with your critical infrastructure segments.
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