Not only are Bitcoin wallets and exchanges vulnerable to security breaches but the heart of bitcoin i.e. Blockchain can easily be infected by permanently hosting malware inside it Bitcoin’s blockchain is designed such that it also allows injection of non-financial data through data insertion methods. This data can be either text messages or pictures up to 60-90 KiB in size or more by encoding arbitrary data as standard transactions. 2.24 2.23 2.22 2.21 2.20 2.19 2.18 2.17 2.16 2.15 2.14 2.13 2.12 2.11 2.10 2.9 2.8 2.3 2.4 2.5 2.6 2.7 2.2 2.1 2.0 1.0 According to a research done by German researchers from the RWTH Aachen University, over 1,600 files are stored in blockchain. Eight of those files contain objectionable content i.e. Child abuse imagery , two files contain 274 links to child porn sites . Read detail here Among popular images stored in bitcoin’s blockchain are: JPEG image of Nelson Mandela , two nude images of child abuse (which I can’t share) and an image of Mr. B