Ddos – Multiple Danish financial institutions

Over 9–11 January 2023, pro-Russian hacktivists ran sustained DDoS attacks against Danish financial institutions and public bodies. Danmarks Nationalbank was hit on the Monday and Tuesday. From Tuesday morning, IT supplier Bankdata was also among the targets, and seven of the eight banks running on its platform had websites and online banking unavailable.

Banks reported as affected included Sydbank, Jyske Bank, Ringkjøbing Landbobank, Sparekassen Sjælland-Fyn, Skjern Bank, Djurslands Bank, Kreditbanken and Arbejdernes Landsbank. Danske Bank also reported an attack on 10 January.

Impact was confined to availability of public-facing websites and online banking. Nothing was breached behind them and no data was taken — Nationalbanken's site stabilised the same afternoon.

On attribution: Danish reporting at the time pointed at Killnet, which claimed responsibility. International reporting named NoName057(16), which claimed attacks on Sydbank, Sparekassen Sjælland-Fyn, BankInvest and Jyske Bank on its Telegram channel. The two groups operated in overlapping pro-Russian hacktivist circles and both claims are on record; this entry does not pick one.

On Bankdata's role: Bankdata was a target of the DDoS, not a route into the banks. Its systems were not compromised, and it was not used as a vector to reach its customers — the banks were separately and directly targeted, several of them named individually by the attackers. The simultaneity of Bankdata's disruption and unavailability at banks on its platform was noted in contemporaneous reporting; no supplier-compromise mechanism was established, and none should be inferred.

• TV 2 — Stribe af banker ramt af cyberangreb
• TV 2 — Prorussisk hackergruppe står bag angreb mod danske banker
• DR — Flere danske banker ramt af cyberangreb: Pilen peger på den russiske gruppe Killnet
• DR — Nationalbanken ramt af cyberangreb
• Version2 — Nationalbanken og Bankdata ramt af DDoS-angreb
• TV 2 — Danske banker og myndigheder ramt af flere dages intensive hackerangreb
• TV 2 — Flere netbanker lagt ned af cyberangreb
• Infosecurity Magazine — Multiple Danish Banks Disrupted By DDoS Cyber-Attack
• BankInfoSecurity — Danish Banks Are Targets of Pro-Russian DDoS Hacking Group