Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!cs.utexas.edu!usc!polyslo!vlsi3b15!vax1.cc.lehigh.edu!sei.cmu.edu!krvw From: ZDEE699@ELM.CC.KCL.AC.UK Newsgroups: comp.virus Subject: RE: VACATION Virus Reported on INFO-VAX List (VAX/VMS) Message-ID: <0014.y8907121814.AA00631@ge.sei.cmu.edu> Date: 7 Jul 89 13:32:48 GMT Sender: Virus Discussion List Lines: 70 Approved: krvw@sei.cmu.edu In VIRUS-L Digest, Monday, 3 Jul 1989, Volume 2 : Issue 147, Brian D. McMahon writes: >The following recently appeared on INFO-VAX; [...] > >>Date: 26 JUN 89 22:05:24.55-GMT >>From: INFOVAX@FRIPN51.BITNET >>To: INFO-VAX@KL.SRI.COM >>Subject: RE: automatic mail answering service : WARNING, MAY BE VIRUS >> >>TAKE CARE: the program VACATION (distributed on a mailing list) is a >>potential VIRUS for ALL the people registered on this list if used >>with no modifications. It will reply to the list, so to itself...and >>so on... And you will be on vacation, so you will not stop it quickly. [...] >> >>Bernard PERROT >>Institut de Physique Nucleaire >>Orsay - France - The moderator of VIRUS-L, Kenneth van Wyk answers: >[Ed. It appears to me to be more a case of an infinite mail loop than >anything that could be called a virus. [...] [...] > If the message goes out to the list, and the VACATION >program replies, you have an endless cycle. As Ken van Wyk said, this is a case of infinite mail loop. There is probably nothing wrong with the VACATION program, and the remedy lies in the list moderator/management's side. To avoid this problem of infinite mail loop when VACATION is run, or a gateway is shutdown, many fileservers use a different address to receive commands and to send information. So if the data is returned to the sender (in this case the listserver), it ends-up in a different account and is NOT sent back again. Examples: send commands to: and the server answers with id: so if the data "bounces back", it is returned to the id NISTLIBD where it is not processed again, and dies there. send articles to: and the distribution is with id: etc. etc. The point is that for some reason (can you explain, Ken ?) bitnet listservers use the same ID to send and receive mail. Before VIRUS-L was moderated, messages bouncing back from gateways were redistributed again since the return path for bounced messages was the sender: Now, I believe that most of the time, the messages are sent by the moderator, to the postmaster of the remote site, who sorts-out the problem with the user on the remote computer. But few lists are moderated, and perhaps it could be time to think about a way to stop these loops which I agree are very irritating to other users. Olivier Crepin-Leblond Computer systems & Electronics, Dept. of Elec. Engineering, King's College London, England ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ |Olivier M.J. Crepin-Leblond | - If no-one can do it | |JANET : | then do it yourself | |BITNET : | - If you can't do it, | |INTERNET: | then P A N I C ! ! | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^