Hi, putty-0.66-installer.exe loads and executes DWMAPI.dll or UXTheme.dll from its "application directory". For software downloaded with a web browser the application directory is typically the user's "Downloads" directory: see , and for "prior art" about this well-known and well-documented vulnerability. If an attacker places one of the above named DLL in the user's "Downloads" directory (for example per "drive-by download" or "social engineering") this vulnerability becomes a remote code execution. Proof of concept/demonstration: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1. visit , download , save it as UXTheme.dll in your "Downloads" directory, then copy it as DWMAPI.dll; 2. download putty-0.66-installer.exe and save it in your "Downloads" directory; 3. execute putty-0.66-installer.exe from your "Downloads" directory; 4. notice the message boxes displayed from the DLLs placed in step 1. PWNED! See , and plus and for details about this well-known and well-documented BEGINNER'S error! stay tuned Stefan Kanthak Timeline: ~~~~~~~~~ 2015-12-24 sent vulnerability report to author NO REPLY, not even an acknowledgement of receipt 2016-01-02 resent vulnerability report to author NO REPLY, not even an acknowledgement of receipt 2016-03-01 report published # Iranian Exploit DataBase = http://IeDb.Ir [2016-03-06]