The Cryptolocker malware requires people to pay the ransom for their data in bitcoins. This may help drive up the price if enough people are infected.
However, one of the podcasts I was listening to said that a security company registered one of the random domains that Cryptolocker checks as its master control server so that they could measure the number of people who were infected. Their numbers showed around 15,000 unique IPs per week contacting their server. The ransom has been lowered to 0.5 BTC so if all 15k people paid the ransom this mean about $7.5 million dollars a week at current prices.
I'm not sure how much that would effect the price of bitcoin.
