PIX 515E Crashing Same Time Each Day

Hi All,

I have a PIX 515E running 6.3(5)

For the last few days at approx 9:30 each morning we are unable to do all
outbound traffic except I am still able to VPN into the network.  I am also
unable to SSH directly into the PIX from the outside.

The last syslog entry each day is the same and it is:
11/3/2006 9:26  Local4.Error    192.168.10.33   Nov 03 2006 08:54:29:
%PIX-3-710003: TCP access denied by ACL from 204.74.68.16/33211 to
outside:xxx.xxx.xxx.xxx/ssh
11/3/2006 9:26  Local4.Warning  192.168.10.33   Nov 03 2006 08:54:29:
%PIX-4-402106: Rec'd packet not an IPSEC packet. (ip) dest_addr=
xxx.xxx.xxx.xxx, src_addr= 204.74.68.16, prot= tcp

All the "last" syslog entries are from the same source IP

Once the traffic stops we start getting the following log entries:
11/3/2006 9:44  Local4.Warning  10.180.250.254  Nov 03 2006 16:42:40:
%PIX-4-106023: Deny tcp src inside:192.168.4.25/1197 dst
outside:xxx.xxx.xxx.xxx21 by access-group "inside"

Not all attempts to access the Internet are logged.

Rebooting the firewalls does not fix the issue.

The Internet comes back in about 1 hour.

It looks like I am being attacked.  Is this a vulnerability is Cisco's SSH?
Will upgrading to 7.0 software fix the issue?

Should I worry about my internal network being compromised?

Thanks for any help you can offer.


-- 
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.5.430 / Virus Database: 268.13.28/518 - Release Date: 11/4/2006
5:30 PM