A story in todays Press of Atlantic City cited Sobig.A and Sobig.B viruses as being on the list of the biggest e-mail viruses of all time. The e-mail message that carries the sobig.F has the subject line "RE: Details" and the message; "Please see attached file for details" If a recipient clicks on the attachment, which can have multiple names ending in the .pif file extension, the computer will be infected.

The viruses will then send itself out to names found in the vitim's address book and will use one of these names to forge a return address. As such, the infected party may not quickly learn of the infection, while an innocent party may get the blame for helping to propagate it.