Nearly 90 per cent of Fortune 500 companies in the US have potentially been affected by the Zeus trojan, according to an RSA Security study released yesterday.
The security firm's FraudAction Anti-Trojan division analysed data stolen by Zeus from infected computers in August, reports CNET. After tracing the data back to individual IP and email addresses, RSA was able to identify the source of the computers used in the Zeus botnet.
"Domains individually representing 88 per cent of the Fortune 500 were shown to have been accessed to some extent by computers infected by the Zeus trojan," the study revealed.
RSA added that when it analysed the compromised data it found on the websites used as dumping grounds for data stolen by Zeus, it found compromised email addresses for three out of five Fortune 500 firms.
The report also noted that it didn't even look at around 20 consumer-facing brands such as Google, due to the huge volume of data these sites already have on the web.
Zeus was first identified in 2007, and is still active today, with compromised computers having been found in a total of 196 countries.
RSA is the security division of IT giant EMC, itself a Fortune 500 company.
