As I recall, EICAR has been around for years. It's not 'new', by any stretch of the imagination. EICAR might help inform you if your AV engine is running; it

As I recall, EICAR has been around for years. It's not 'new', by any stretch of the imagination. EICAR might help inform you if your AV engine is running; it won't tell you how effective your AV engine is against current threats. It's really only useful for developers to tell if their AV engine is scanning anything at all... consumers don't really get much benefit from it.