The first half of 2003 was generally quiet in terms of virus activity. However, this does not mean there was total calm, as in these first six months there were two virus epidemics, involving the worms SQL Slammer and Bugbear.B. This period could be classified as a transition period, where we saw the first signs of the new virus trends. Even though e-mail worms that use so called social engineering and exploit vulnerabilities in widely-used software have been the culprits of most infections, another type of malicious code is starting to become more widespread: worm/Trojan hybrids. During the first five months of this year, the e-mail worm Klez.I headed the ranking of the virus most frequently detected, according to data collected from the free, online antivirus Panda ActiveScan, but was knocked off the top spot at the beginning of June by the worm/Trojan Bugbear.B. Full Story