The American Radio Relay League, the US national association for amateur radio operators, told members on 16 May 2024 that it was responding to what it called "a serious incident" involving access to its network and headquarters systems. The attack occurred on or around 12 May and disrupted email along with several member-facing services.
Among the systems taken offline was Logbook of The World, the database amateur operators use to submit electronic logs of contacts and have them confirmed by the stations they worked. The ARRL Learning Center, the DXCC awards system and internal accounting systems were also affected. ARRL said the outage was not a fault in the Logbook servers themselves and that Logbook data was secure.
ARRL did not initially say what, if anything, had been taken. It noted that it does not store credit card details anywhere on its systems and does not collect Social Security numbers, and that its member database holds items such as names, addresses, call signs, email addresses and membership dates.
The organization involved the FBI and outside incident response specialists. In a report to members published in August 2024, ARRL described the incident as a ransomware attack by an organized international group using access purchased on the dark web, said the FBI had judged the intrusion unusually sophisticated, and confirmed it had paid a $1 million ransom. Logbook of The World returned to service on 1 July 2024.