Suela-104 2 infection on OSX but not on XP. Where/how save mode: OSX/ Parallels5/XP?

System MacOSX 10.6.8 + Parallel 5.0 + Windows XP virtual machine

1 year ago my Mailaccount (Arcor.de) was abused (Mailerdaemons of mails I do not sent):
I had an infecion with SUELA-1042. The error massage was made by Avast (Mac OSX) but not found by Avira (XP-virtual machine). I thought I deleted the item and had 11 months without troubles and mailerdaemons.

But now I have more problems. Info about infection and deleted item by my antivirus-programm (Avast for Mac):
2120 ARJ-Archive ist corrupted
Unknown error: 42148
Unknown error: 212
error 42137: CPIO-Archive ist corrupted
error 42110: file is a decompression bomb
Suela-1042

My Mailaccount (Arcor.de) is abused again though I changed my password after detecting+deleting the Item.
Virus-scan is without an negativ message but the performance of applications and switching in between is very slow!!!

I haven´t started Parallels again because I fear more damages.
Is there a save mode to start the process? Where do I start the save mode: in OSX ?
How does a save mode work (OSX, Paralles, XP, Time-Machine)?

How can I be sure to delete it on all levels ? I do not use Paralles frequently (OpenOffice + configuration of ISDN-Router) and am not sure whether I have an internet-connection made on the Virtual Machine.

 

Are there no suggestions/ideas/answers for these questions?!