A new Java bug has been added to the Blackhole Exploit Kit. The bug is a complex Java issue, which has patches available from Oracle. The new exploit was actually the third attack delivered after the initial landing page was hit. The good news is that the initial exploits that have been released make use of some very odd strings, particularly around file names encoded inside the JAR file. This means that the VRT has very reliable detection of all variants that we’ve observed in the wild (use SIDs 23273 – 23277)”]
Source: https://blog.talosintelligence.com/2012/07/cve-2012-1723-new-java-attack-added-to.html