Organised crime was responsible for 85 per cent of total data loss in 2009, a study reported by the San Francisco Chronicle reveals.
The Verizon Data Breach Investigations 2010 report was based on statistics gathered by both Verizon and US secret service agencies.
The report found that nearly half - 48 per cent - of all breaches were carried by company insiders, with 11 per cent from disgruntled business partners. Outsiders were involved in 70 per cent of cases, with 27 per cent of breaches planned by a combination of authorised employees acting with outside help.
Methods used to carry out attacks included hacking (40 per cent of data loss), malware (38 per cent) and social engineering tactics (28 per cent). Physical attacks on personnel accounted for 15 per cent of data loss.
Verizon and US secret services studied more than 900 million breaches taking place over a six-year period.
“By adding our data to the secret service's we were able to build up a better picture of data breaches, with many results found to be the same as earlier reports," said Matthijs van der Wel, managing principal for the forensics team at Verizon.