Kaspersky has openly admitted they had received NSA hacking tools that were attached to a larger file that was deemed a security risk. They say that when they realized what they had they deleted it from their system. Great article on the subject. 

https://www.reuters.com/article/us-cyber-summit-kaspersky/kaspersky-acknowledges-taking-inactive-files-in-pursuit-of-hackers-idUSKBN1D328B