Researchers at Kaspersky Labs have found malware which, unusually, does not install any files on its victims PCs.
The researchers aren’t quite sure how unusual it is, describing it as both “unique” and “very rare”, but no matter how scarce this type of malware is it does sound rather nasty as it “… uses its payload to inject an encrypted dll from the web directly into the memory of the javaw.exe process.” That mode of operation means Windows and MacOS are both affected by the exploit, which is hard for many antivirus programs to spot given it runs within a trusted process.
It doesn't install files initially, however it does disable UAC in order to install further nasties (in this case, Lurk).
It only affects Java 6.0.27 and previous but we all know how good users are at updating software
Story @ The Register
Analysis @ Kaspersky Blog (Securelist)