Cybercriminals are using advanced ad-targeting capabilities to precisely deliver malware. Security vendor Invincea says it has detected many instances of people stumbling across malicious advertisements that are shown only to them. The ads are supplied that redirect visitors to landing pages on legitimate websites that have been hacked. The landing pages those ads redirect to are up for as short as 10 minutes to four hours. The malware is modified so frequently that it is hard for security products to detect, he said. A white paper on the scheme will be released Friday.”]