You should be with this specific file. A file named DOWNLOAD FILE – HALF-LIFE: OPPOSING FORCE.RAR —especially with the broken character encoding ( – )—is a classic hallmark of malware or a "browser hijacker" scam .
: Do not open this .rar file. If you have already downloaded it, delete it immediately and run a full system scan with a reputable antivirus like Malwarebytes or Windows Defender . DOWNLOAD FILE – HALF-LIFE: OPPOSING FORCE.RAR
: Legitimate digital distributors (like Steam) or modding communities (like ModDB) do not package files with "DOWNLOAD FILE" in the title. You should be with this specific file
: The official Steam store page is the safest way to get the game. It is frequently on sale for a very low price. If you have already downloaded it, delete it
If you want to play the game safely, I recommend using these official or highly-trusted sources:
: Files like this often contain "Adware," "Trojans," or "Ransomware." Instead of the game, you may end up with a program that steals your passwords, tracks your browsing, or locks your files. Safe ways to get Half-Life: Opposing Force: