Can you tell me if this is an attack?

Well, those could be the result of spammers sending out messages and using your email address, (ie. the one where you are receiving those bounce messages), as the From or Reply-To address. If your system is secure and clean, meaning the messages aren't being sent by malware (spam bot, mailing virus, etc.) on your system, then this is the most likely cause.

 

Rita had a similar problem.

https://www.wilderssecurity.com/showthread.php?t=60367

 

Similar, but probably a bit different. We believe in Rita's case her AOL login was broken into elsewhere, (meaning not on her system locally but more likely a brute force password guessing routine run against her account from the spammers system), and then the spam was sent from the spammer logged into her account on their (the spammer's) PC. The chief sign/proof of this was that the outgoing emails were all still in her Sent Mail folder up on the AOL server and there were no signs at all of a breaking on her PC.

This case could be much simplier in that no break in occurred (either locally or at Frank's ISP account), and the From address was simply forged to be Frank's address. A detailed analysis of the headers in the bounce messages might help narrow it down.