While setting a port for Symantec to query XP Pro workstations for virus
updates, I noticed two machines that had firewall rules (exceptions in WinXP
firewall parlance) that were in unreadable charcaters, such as an asian font
set that couldn't be displayed. The rule name was in blocks or in other
unreadable characters. The user of these two workstations is notorious for
downloading asian TV shows over bit torrent, and visiting anime and other asian
sites.
I deleted the two firewall rules (DOH! I should have just disabled them) and
now IE and Mozilla browsers do not work at all. I can ping out of these two
machines, and as long as I use an IP address, these machines can ping anywhere
in the Internet. However, if any call to DNS is requires, either with a
browser or ICMP, it fails.
Has anyone had a similar experience or seen this kind of behavior. My fear is
that one of the "special Korean download programs" that this user admits
installing has altered the browser or -- even worse - the XP TCP/IP stack with
hooks into a trojan or spyware product. I tried disabling the firewall to
allow all traffic in and out, but to no effect. No DNS functionality. My
packet traces are inconclusive and my IDS is not alerting on anything in or out
of these two work stations.
Any ideas? At this point I know I am going to have to reload, but from a
forensic stand point, I am curious if any one else has seen this kind of
beavior before.
Thanks.
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