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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: New mail blocks result of Ralsky's latest attacks?
on Fri, Oct 10, 2003 at 08:47:51PM +0530, Suresh Ramasubramanian wrote: > Set up header checks in sendmail / postfix to block all mail with > Received: headers showing Ralsky IPs. PCRE header checks in postfix > would be like - <snip> Sendmail rulesets to block Ralsky: KRalsky1 regex [email protected] ^.*(\[|\(|\s)211\.158\.[3456789] KRalsky2 regex [email protected] ^.*(\[|\(|\s)218\.70\.1[345] KRalsky3 regex [email protected] ^.*(\[|\(|\s)219\.153\.1[45] KRalsky4 regex [email protected] ^.*(\[|\(|\s)218\.10\.57 KRalsky5 regex [email protected] ^.*(\[|\(|\s)218\.70\.1[01] KRalsky6 regex [email protected] ^.*(\[|\(|\s)218\.70\.[89] KReceivedChecks sequence Ralsky1 Ralsky2 Ralsky3 Ralsky4 Ralsky5 Ralsky6 HReceived: $>check_header_Received Scheck_header_Received R$* $: $1 $| $(ReceivedChecks $&{currHeader} $) R$* $| @SPAM $#error [email protected] 5.7.1 $: "550 Message rejected; suspected spam signature." R$* $| $* $: $1 This will not help to block direct SMTP AUTH attacks; but they should block mail from other compromised servers, provided they don't munge the headers. I've been running these rules for several weeks without incident. HTH, Steve -- hesketh.com/inc. v: (919) 834-2552 f: (919) 834-2554 w: http://hesketh.com Book publishing is second only to furniture delivery in slowness. -b. schneier
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