In a bizarre investigation, Belgium police have identified a member of the Anonymous Belgium hacker collective while investigating an arson case at a local bank.

The perpetrator, a 35-year-old man from the Belgian city of Roeselare, was initially arrested after throwing a Molotov cocktail at the Crelan Bank office in Rumbeke, a suburb of Roeselare, back in 2014.

Police tracked down the suspect because he dropped a USB thumb drive on the ground while/after throwing the Molotov cocktail.

Data on the thumb drive led police to a local man identified in court documents only by Brecht S..

Lost USB thumb drive leads police to Anonymous hacker

A subsequent house search and investigation into the man's background and computer devices revealed a long history of cyber-crimes.

They said that in addition to throwing a Molotov cocktail at a Crelan Bank office, Brecht also launched DDoS attacks against Crelan's e-banking portal, bringing the site down for hours on numerous ocassions.

In court, Brecht said he attacked the bank because Crelan officials refused to meet with him following the disappearance of €300,000 ($342,000) from his mother's bank account following the divorce from his father. He justified the attacks as revenge for his mother's financial losses.

The man's penchant for launching DDoS attacks wasn't an isolated case, though, according to the prosecution.

Belgian police said the man was also an active member of the Anonymous Belgium and Cyber Crew hacking groups, participating in some of their past operations, including one aimed at FIFA, the international soccer/football federation.

Brecht also orchestrated DDoS extortions, with one aimed at an unnamed pizza restaurant. Investigators said the suspect attacked and brought down the restaurant's website with DDoS attacks on numerous occasions, and asked for a ransom payment to stop his attacks.

Police also track down co-conspirator

The investigation into Brecht also exposed a co-conspirator -- a 44-year-old man from Bruges, with whom Brecht had exchanged hacking tools in the past via Facebook.

According to Belgian news site Het Laatste Nieuws, the two were involved in many other cyber-attacks, but investigators couldn't pin or confirm some of these incidents because Facebook refused to cooperate in the investigation.

HLN reported last week that Brecht received an 18 months prison sentence for his cyber-crimes, and was ordered to pay €3,000 ($3,400) to Crelan Bank as compensation for the e-banking portal's downtime.

Brecht's recent jail term will be added on top of a three-year prison sentence for arson (related to throwing the Molotov cocktail). The first sentence's execution was delayed so Brecht could receive counseling for psychological problems.

Brecht's co-conspirator, the 44-year-old man from Brugge, was let off without a prison sentence, being ordered to pay a €1,200 ($1,370) fine.

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