I'm pretty sure they are viruses. Can you tell us the names of the files? Just because they're different doesn't always mean they're randomly generated. Secondly, What makes you think they're coming from ntlworld email addresses? The first one has an ntlworld email address as a From header, but since they're obviously spammed mails I'd ignore the From and To headers anyway.
You have three choices really:
- Ignore them - just don't open the attachments
- Forward these details to the abuse department at t-online.de - this is the (German) ISP that those IP addresses belong to
- Forward these details to ntl's abuse department at abuse@ntlworld.com - assuming ntl is your ISP - and let them do the German translation.
Never a bad idea to do a full scan of your system with up-to-date definition files, too!