Client honeypots are tools that actively search servers for malicious data like malware, exploits, malicious PDF files, etc.
The Polish Chapter just released a new version of Capture-HPC originally developed by Christian Seifert and Ramon Steenson of the New Zealand Chapter. Capture-HPC focuses primarily on attacks against, or involving the use of, Web browsers.
It is available for download as binary Debian package on Polish Chapter webpage:
Source code is made available via github: