A cyberattack last Sunday on the computer systems of Hellenic Post (ELTA) is not an isolated incident, but the latest in a series of attacks on state agencies and state-owned companies over the past year, authorities say.
What is obvious in all such attacks is the hackers’ persistence in penetrating a network and the similarity in their demands – payment in some cryptocurrency to release their hold on the data.
In February 2021, hackers attacked about 150 computers at Hellenic Defense Systems, a manufacturer of small arms, artillery and munitions, locking files containing financial and legal data, contracts, as well as emails. They asked for hundreds of thousands of euros in bitcoins to send an encryption key that would unlock the files. The company refused to negotiate. Forensic research showed the malware had entered the company’s systems through phishing in the form of emails providing links. The mails were sent for a month before a careless employee clicked on the link in one, unleashing the malware, named Avaddon. It was the same malware used in other attacks in 2021, notably on a Florida police precinct.
A cyber defense unit from Army Headquarters spent a month at the company’s offices to redesign the network, install a new firewall and implement new security protocols. Employees were forbidden to use USB sticks.
Another attack targeted the Municipality of Thessaloniki, Greece’s second-largest city, on July 21. Municipality terminals displayed a message: “Thessaloniki, you’re screwed.” Officials refused to bow to demands for ransom and the hackers published some leaked documents. The municipality was also the target of two attacks on the same day, September 30, 2021, which officials say were dealt with successfully.
In January 2022, a server at the National Health System serving the accounts departments of Attica hospitals Asklipieio and Sotiria was attacked with ransomware. Accounts departments had to switch to paperwork for days before the system was fixed. Hospital administrations say they refused to negotiate.