In between then and now there has been a lot of rumour and debate about all aspects of this attack with many truths and mistruths being carried in public. In this attack a PDF file was used to exploit the Adobe Acrobat, Reader, and Flash Player Remote Code Execution Vulnerability (CVE-2009-1862/BID35759). This PDF installed a Trojan horse which was an earlier version of the current Trojan.Hydraq. Clear all system event logs. This means the remote attacker has the ability to see in real time any user interface activity as if they were sitting right next to the user. As described in the previously posted blog (Hydraq - An Attack of Mythical Proportions), an unpatched Internet Explorer vulnerability (BID 37815) was used as one of the propagation vectors for this particular Trojan.Hydraq attack. This security hole allows remote exploitation, which means that attackers can run any malicious code of their liking on a victim’s machine by taking advantage of the vulnerability. The number of computers we have observed being attacked or have been attacked is low as borne out by our field detection statistics. The use of browsers other than Internet Explorer by an increasingly large number of people may have helped limit the “attack surface” by reducing the number of computers vulnerable to the Internet Explorer vulnerability used in this attack. Prevention &amp; Mitigation Trojan.Hydraq has been known to be spread through specially crafted PDF files and also through malicious Web sites. Potential attack scenario: When using this vulnerability the most likely attack vector used in this case is targeted emails containing legitimate looking PDF documents sent to high level employees