Since these are low traffic groups, any SPAM really sticks out.
I've deleted those messages, and reported the users. Their accounts
are short use spam generation accounts, so I doubt reporting them will
have any real effect.
These users do not show up in the list of users for GLPRO or
AFTERGRASP groups, yet they seem to have posted their SPAM? How?
In the Google Groups support group, they say it's not some now breach
allowing spammers to post, but rather they join a group, post spam,
and then unsubscribe.
To combat this, for now on all messages from new members are moderated.
I hope this can prevent this annoying problem from reoccurring.
Sorry for the SPAM.