The Italian Honey Project

[..] Dmitry Tarakanov, a researcher at Kaspersky Lab who has studied the two families said that there was a code transfer from Zeus to SpyEye in the immediate aftermath of the source code being transferred to the SpyEye author. For example, the SpyEye author grabbed a Zeus feature that allowed the malware to force Web browsers on infected systems to load malicious HTML served by the botnet, even in cases where the host had a recent version of the page in question (say, an electronic banking site) stored locally in its browser cache. “SpyEye could not intercept the cached html-code,” Tarakanov wrote in an e-mail. “So the author of Spyeye had seen that part of the code where Zeus replaces the cache as well and added that part of code into his own source code of SpyEye. [..] “

via SpyEye and Zeus Malware: Married Or Living Separately? | threatpost.