Using RegEx in JSON Schema

To test a string value (not a property name) against a RegEx, you should use the "pattern" keyword:

{
    "type": "object",
    "properties": {
        "progBinaryName": {
            "type": "string",
            "pattern": "^[A-Za-z0-9 -_]+_Prog\\.(exe|EXE)$"
        }
    }
}

P.S. – if you want the pattern to match the key for the property (not the value), then you should use "patternProperties" (it’s like "properties", but the key is a RegEx).