Beirut officials have arrested three suspects believed to be behind what local authorities are calling the biggest hack in Lebanon's history.

The arrests took place last week and included what police believe to be the main hacker, one of his accomplices, and a local businessman, according to Lebanese daily newspaper Al Akhbar.

Hacker breached security agencies, telecoms

Officials said the hacker broke into the IT systems of security agencies, government departments, and private companies, such as two cellular telecommunications companies, and a large ISP.

It was later revealed in subsequent media coverage that the large ISP was state-controlled Ogero Telecom, where the hackers gained full control of the company's email system and would have been able to send messages posing as the company.

But in most cases, officials said the hacker only dumped data from the breached companies, which he later tried to sell to unknown parties.

Lebanese media believes the third arrested suspected, the local businessman, might have been the one buying the data, or the one who hired the hackers in the first place.

Authorities didn't release the names of the three arrested suspects, but the Al Akhbar newspaper claims the businessman sits on the Board of Directors of a prominent Lebanese bank.

Hack discovered by local state-controlled ISP

The hack was discovered by Ogero at the end of June, and the ISP notified Lebanese authorities about the intrusion into its system, which later led to the three arrests last week.

Prior to last week's events, the largest hacking-related incident associated with Lebanon was years-long cyberespionage and hacking campaign which security researchers tracked down to a building in Beirut that housed the General Security Directorate, Lebanon's intelligence agency. More details about that cyber-espionage operation are available in the EFF and Lookout's Dark Caracal report [PDF].