https://arstechnica.com/information-technology/2017/08/code-chunk-in-kronos-malware-used-long-before-malwaretech-published-it/

A chunk of code found in the Kronos bank-fraud malware originated more than six years before security researcher Marcus Hutchins is accused of developing the underlying code, a fellow security researcher said Friday.

The conclusion, reached in an analysis of Kronos published by security firm Malwarebytes, by no means proves or disproves federal prosecutors' allegations that Hutchins wrote Kronos code and played a role in the sale of the malware. It does, however, clarify speculation over a Tweet from January 2015, in which MalwareTech—the online handle Hutchins used—complained that a complex piece of code he had published a month earlier had been added to an unnamed malware sample without his permission.