If "Ghamstor" is indeed a game trainer or cheat utility, "ghamstor-15.rar" likely contains the executable file and necessary documentation to alter the memory values of a running game process.
Even if the file isn't outright malicious, it may come bundled with unwanted software. Adware can hijack browsers, change default search engines, and spam the user with pop-ups, severely degrading the user experience. ghamstor-15.rar