Security Incidents mailing list archives

Re: Strange SMTP sessions with 'helo=<large negative number>' syntax


From: mis () seiden com
Date: Thu, 29 Dec 2005 00:33:03 -0800

this has been going on for weeks.

i believe they're all open proxies or spambots.

(some of us use this as an oracle for open proxies.)

On Wed, Dec 28, 2005 at 04:39:14PM -0500, max wrote:
Hello all,
I find this inmy logs throughout the day today:

Dec 28 16:35:52 finn postfix/smtpd[13320]: NOQUEUE: reject: RCPT from 
pcp0012209034pcs.blairblvd.tn.nash.comcast.net[69.245.57.210]: 501 <-1217882552>: Helo command rejected: Invalid 
name; from=<shuu () grandlakeindexing com> to=<dylanfans-unsubscribe () dylanirvana com> proto=SMTP helo=<-1217882552>

Notice that helo section is a negative number (which is why my postfix rejects the message)
There are about 5 messages a minute at its peak, and this has been going on most of the day today (EST time zone)
Some of the connecting IP's are listed in various black lists, such as OPM.

Has anyone noticed this as well? Is this a virus or just some new spam tool?
Some more rejected messages below:

Dec 28 16:37:50 finn postfix/smtpd[34627]: NOQUEUE: reject: RCPT from 
cpe-66-75-65-130.socal.res.rr.com[66.75.65.130]: 501 <-1218008120>: Helo command rejected: Invalid name; from=<Laudat 
() gma-consulting-fr com> to=<dylanfans-unsubscribe () dylanirvana com> proto=SMTP helo=<-1218008120>

Dec 28 16:37:54 finn postfix/smtpd[13320]: NOQUEUE: reject: RCPT from unknown[219.130.49.89]: 554 Service 
unavailable; Client host [219.130.49.89] blocked using opm.blitzed.org; Open proxy - see 
http://opm.blitzed.org/219.130.49.89; from=<burkel () greenacresmortgage com> to=<max () neuropunks org> proto=SMTP 
helo=<-1209697480>

Dec 28 16:38:10 finn postfix/smtpd[34627]: NOQUEUE: reject: RCPT from 194-144-9-218.du.xdsl.is[194.144.9.218]: 501 
<-1209697480>: Helo command rejected: Invalid name; from=<brenno () grandslamtennistours com> to=<max () neuropunks 
org> proto=SMTP helo=<-1209697480>

Thanks,

Max


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