Cyber Incident Victim: City of Grenoble
Date:
May 2021
Location:
France
Summary
The City of Grenoble experienced a cyberattack involving a DDOS attack targeting its networks, causing temporary disruptions to services. The incident was resolved swiftly with assistance from telecommunications provider SFR, restoring system functionality by early afternoon without reported data compromise or exfiltration.
| CIA Posture | Motives | Tactics, Techniques & Procedures |
|---|---|---|
| Available to members | 1 motive | 1 technique |
| Threat Actors | Type | Location |
|---|---|---|
| 0 actors | Available to members | Available to members |
Description
On May 21, 2021, the networks of Grenoble-Alpes Métropole and the City of Grenoble experienced a distributed denial-of-service (DDOS) attack. The attack disrupted normal operations by overwhelming the systems with traffic, though the specific duration or peak intensity of the disruption was not detailed in public reports. Local media outlet Le Dauphiné first reported the incident, while FranceInfo noted that authorities acted swiftly to mitigate the attack. Technical teams collaborated with telecommunications operator SFR to restore network functionality, achieving recovery by the early afternoon of the same day. No evidence suggested data exfiltration, ransomware deployment, or compromise of internal systems beyond the temporary service interruption. The attack exclusively targeted network availability, with no public indication of secondary malware infections or lateral movement within the infrastructure.
The coordinated response between municipal IT staff and SFR effectively contained the incident within hours of detection. Officials did not disclose the attack’s origin, claimed perpetrators, or precise motives, focusing instead on operational restoration. Service normalization occurred without reported residual impacts on public administration functions or data integrity. No follow-up statements referenced ongoing vulnerabilities, forensic findings, or adjustments to defensive protocols beyond the immediate remediation. The incident concluded with restored operations and no supplementary reports of extended downtime or cascading effects on related municipal services.