www.virustotal.com / www.metascan-online.com are two very usefull online tools

they are multi antivirus engines that you can use for checking suspicious files
Virustotal can also check URLs for blacklisting. Metascan can also check IP for blacklisting

see example here, just checked a fake mail attachment

https://www.virustotal.com/en/file/087044ca9be10f23f3af9c4f15a41b11c33b939df11944c4a2d87151136425bc/analysis/1434658616/

https://www.metascan-online.com/en/scanresult/file/cd4cb5f45ce54ca5be3547f014130b06