We've been seeing these as well. But not just to personal firewalls. I've seen them on cable modems, dsl lines, and corporate T-1's. I'm cross-posting this because I've seen references to this type of activity on multiple lists. I'm a bit baffled by this. The source port is always 53, with a random destination port. And they appear to be replies to me as well. A possibility is that we're being used as decoy addresses in some sort of scanning. However, since the addresses are *SO* random, this tends to rule out nmap as a scanner using --randomize-hosts. Nmap will randomize, but when fed a really large network block to scan, it will scan within three or so class C networks at a time. Are there other scanning tools with the ability to use spoofed decoy addresses, yet provide better randomization than nmap when scanning? Keith T. Morgan Chief of Information Security Terradon Communications keith.morganat_private 304-755-8291 x142 > -----Original Message----- > From: Ben Alexander [mailto:balexanderat_private] > Sent: Monday, May 14, 2001 10:25 AM > To: 'n9ubhat_private' > Cc: 'focus-linuxat_private' > Subject: RE: DNS Floods to personal firewalls > > > I received these as well, and I know a few others that > receive them also. > Using arin whois, here is what I put together: > > [140.239.176.162/17221] HarvardNet > [165.121.70.75/64551] Earthlink > [194.205.125.26/41123] European Regional Internet Registry > [194.213.64.150/47642] European Regional Internet Registry > [202.139.133.129/41595] Asia Pacific Network Information Center > [203.194.166.182/38808] Asia Pacific Network Information Center > [203.208.128.70/12235] Asia Pacific Network Information Center > [207.55.138.206/61929] "Verio, Inc." > [208.184.162.71/53567] Abovenet Communications > [209.249.97.40/45714] Abovenet Communications > [212.23.225.98/57974] European Regional Internet Registry > [212.78.160.237/29368] European Regional Internet Registry > [216.220.39.42/21602] "Myna Communications, Inc." > [216.33.35.214/21092] Exodus Communications > [216.34.68.2/45906] Exodus Communications > [216.35.167.58/32470] Exodus Communications > [62.23.80.2/55543] European Regional Internet Registry > [62.26.119.34/56523] European Regional Internet Registry > [63.209.147.246/54734] Level 3 Communications > [64.14.200.154/32735] Exodus Communications > [64.37.200.46/65042] Exodus Communications > [64.56.174.186/14237] Exodus Communications > [64.78.235.14/17768] "Verado, Inc. (Firstworld Communications)" > > > -----Original Message----- > > From: ssratat_private [mailto:ssratat_private] > > Sent: Sunday, May 06, 2001 10:24 PM > > To: FOCUS-LINUXat_private > > Subject: DNS Floods to personal firewalls > > > > > > There seems to be lots of these happening. They appear to be some > > kind of DNS replies, but are getting rejected by the > firewall - these > > reports are coming from the Linux Router Project (LRP) list. > > > > I've asked for a tcpdump to be sent, as I've not seen > these; could it > > be a DNS server somewhere was taken over, or some kind of > attack tool > > generates the same spoofed addresses? > > > > So far the main report details are the reject lines from ipchains in > > /var/logs/messages. > > > > Here is a portion one person posted: > > > > May 6 14:39:57 tifa kernel: Packet log: input DENY ppp0 PROTO=6 > > 208.184.162.71:34387 203.59.110.14:53 L=44 S=0x00 I=0 F=0x0000 T=236 > > (#37) > > May 6 14:39:57 tifa kernel: Packet log: input DENY ppp0 PROTO=6 > > 202.139.133.129:47571 203.59.110.14:53 L=44 S=0x00 I=0 > F=0x0000 T=241 > > (#37) > > May 6 14:39:57 tifa kernel: Packet log: input DENY ppp0 PROTO=6 > > 203.208.128.70:16146 203.59.110.14:53 L=44 S=0x00 I=0 F=0x0000 T=247 > > (#37) > > May 6 14:39:57 tifa kernel: Packet log: input DENY ppp0 PROTO=6 > > 194.205.125.26:42786 203.59.110.14:53 L=44 S=0x00 I=0 F=0x0000 T=242 > > (#37) > > May 6 14:39:57 tifa kernel: Packet log: input DENY ppp0 PROTO=6 > > 209.249.97.40:34126 203.59.110.14:53 L=44 S=0x00 I=0 F=0x0000 T=236 > > (#37) > > May 6 14:39:57 tifa kernel: Packet log: input DENY ppp0 PROTO=6 > > 216.33.35.214:15928 203.59.110.14:53 L=44 S=0x00 I=0 F=0x0000 T=237 > > (#37) > > May 6 14:39:57 tifa kernel: Packet log: input DENY ppp0 PROTO=6 > > 140.239.176.162:11843 203.59.110.14:53 L=44 S=0x00 I=0 > F=0x0000 T=237 > > (#37) > > May 6 14:39:57 tifa kernel: Packet log: input DENY ppp0 PROTO=6 > > 216.34.68.2:38839 203.59.110.14:53 L=44 S=0x00 I=0 F=0x0000 T=237 > > (#37) > > May 6 14:39:57 tifa kernel: Packet log: input DENY ppp0 PROTO=6 > > 207.55.138.206:24678 203.59.110.14:53 L=44 S=0x00 I=0 F=0x0000 T=238 > > (#37) > > May 6 14:39:57 tifa kernel: Packet log: input DENY ppp0 PROTO=6 > > 216.35.167.58:24169 203.59.110.14:53 L=44 S=0x00 I=0 F=0x0000 T=237 > > (#37) > > > > He has the entire thing in an URL: > > http://members.iinet.net.au/~paulhng/lrp/kernlog.txt > > > > It also appears that the same IPs are reported over and over again. > > It has the markings of some kind of tool I think - but I'm new at > > this. > > > > > > -- > > David Douthitt > > UNIX Systems Administrator > > HP-UX, Unixware, Linux > > n9ubhat_private > > >
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