Another strand of the investigation focused on the accounts established by the fraudsters. "We established where the money would have gone and took it from there," Kirby explained. "Because the bank accounts were outside UK jurisdiction we had to go through diplomatic channels. I'm still waiting for some requests."
Meanwhile, computer forensics examination established that commercial key-logging software had been loaded onto compromised machines. "It was a standard key-logger available on the net from a reputable firm of the type parents use to keep an eye on their children," Kirby said. "The use of legitimate technology meant the software was not picked up by anti-virus scanners. And there was no traffic going into or out of the network so it couldn't be detected that way."
The software used in the scam, iOpus Starr, is normally used for remote surveillance of networked PCs.
The crooks obtained two sets of Swift login credentials, one for an ordinary user and one for a supervisor account, needed to authorise transactions, from two machines. They had also tested the software on another machine. The compromised PCs were then formatted in a failed, rather crude attempt to destroy evidence.
Computer forensics evidence obtained from these machines, CCTV footage from the bank and elsewhere, telephone call records, building access logs and travel records became the principal planks of the investigation. Analysis of the laptops of suspects also played an important role. Since the heist failed, there was never a money trail to follow.
Traces of guilt
The investigation involved a team that varied from seven to 14 officers, at time of peak demand, and stretched over two years.
Following interviews with bank staff, O'Donoghue was arrested and charged. He claimed he was coerced into driving the two hacking suspects to the bank and letting them in.
"O'Donoghue was arrested within the first few days of the operation. His involvement was clear from the CCTV footage which showed him escorting [the hackers] into the bank," Kirby explained. "We took about two more years to identify Mr P and Mr Van O [the hackers]," he added.
Much effort was spent in the painstaking task of examining CCTV footage. From this the two hacking suspects were identified, initially known to the police only as Laptop and Ponytail. O'Donoghue's mobile phone records were seized. He'd changed his phone during the course of the investigation but this failed to throw police off the scent.
Phone call and location records allowed police to identify the two hackers as Belgian Jan van Osselaer, 32, and Frenchman Gilles Poelvoorde, 35. Poelvoorde (Ponytail) was arrested with a USB stick that had the same digital fingerprint as the key-logging program used in the Sumitomo scam, along with instructions on how to carry out the same hack on another bank outside the UK.
Phone records involving van Osselaer and Poelvoorde, in turn, led to the identification of other members of the conspiracy. Other lines of inquiry turned out to be dead ends.