The South African government has lost more than £12m (199m Rand) over the last three years thanks to a cybercrime syndicate using spyware.
The scam has been running since 2005 and is still going on despite the arrest of 32 people. Thieves have targetted various government departments in four provinces. A number of civil servants have also been sacked.
Crooks are using corrupt government officials and suppliers to fix a small piece of kit the size of a memory stick to PCs. This can then access saved and unsaved information, according to South Africa's Mail & Guardian.
The paper said it has taken so long to sort out the problem because officials were originally concentrating on finding the crooks, but now they are focussed on stopping it happening again.
The gang is also believed to have targeted banks in the country.
Geoff Sweeney, CTO with security firm Tier-3, said that spyware attacks are hard to stop because of their unpredictable nature, and because of convergance between viruses, trojans and other malware.
"These fraudsters appeared to be using a sophisticated combination of attacks that consisted of a physical device and a malware component, as witnessed by the fact they have been getting away with their crimes for nigh on three years."
Sweeney said such attacks showed the need for several layers of defences. ®