The sentences followed guilty pleas from all four men at Southwark Crown Court, in connection with a complex electronic fraud using a trojan to steal from bank accounts, that saw them send the proceeds of their crimes to criminal networks operating in Eastern Europe.
According to the prosecution, in early April of this year, more than 50 police officers from the Metropolitan Police's Central e-Crime Unit (PCeU), local council staff and the SCD, the specialist crime directorate, raided multiple addresses in south-east London following an investigation into a criminal network that had been targeting the financial services industry by stealin from bank accounts using a trojan.
According to the PCeU, this was the first operation of its kind involving professionals from law enforcement agencies and the financial services sector.
The police said that the gang are believed to originate from Eastern Europe and had been using servers across the continent as landing sites for phishing emails - carrying the brand logo of NatWest bank, one of the UK's largest banks - and hidden links to the trojan malware.
Once loaded on to a victim's PC, the trojan infection allowed funds to be stolen from bank accounts in real time - effectively `piggy-backing' a legitimate e-banking session - and then transferring the money to a selection of `mule' accounts.
A total of just under £600 000 was stolen and transferred using the trojan, said the police.
By relaying the money to other accounts in foreign countries, this made the task of retrieving the stolen funds difficult, as well as allowing the electronic trail to be hidden from subsequent investigation.
Detective Constable Kevin Brocklesby of the PCeU said that this was a complex investigation which certainly involves other people in Russia, but there was a clear structure to the organisation in the UK.
"In order to withdraw the stolen cash a key element was to obtain UK bank accounts in which to deposit the funds. Plenty of people appear to be willing to accept money into their accounts with no questions asked and they are a crucial cog in this kind of criminal machine", he said.