With the constant rise of the number of Internet users, available bandwidth and an increasing number of services shifting into the connected world, criminals are increasingly active in the virtual world. With improving defensive methods cybercriminals have to utilize more and more sophisticated ways to perform their malicious activities. While protecting the privacy of users, many technologies used in current malware and network attacks have been abused in order to allow criminals to carry out their activities undetected. This poses a lot of new challenges for digital forensics analysts, academics, law enforcement agencies (LEAs), and security professionals. The aim of the International Workshop on Criminal Use of Information Hiding (CUIng) is to bring together researchers, practitioners, law enforcement representatives, and security professionals in the area of analysis of information hiding. However data hiding is understood here in a wider manner than in the academic world i.e. all techniques that pertain to camouflaging/masking/hiding various types of data (e.g. identities, behavior, communication, etc.) are included here.