HIPAA/SECURE:
Security Q/A
January 2003
"Security Solutions: Key Technologies and Practices"
>> Monitoring Log Files <<
by Eric Maiwald, CISSP, CTO,
Fortrex Technologies, Inc.
QUESTION: I understand that I should be monitoring the log
files on my systems. What is the best way to do this?
ANSWER: Monitoring log files is indeed a good practice.
Good information can be found in the event logs of servers, in firewall
logs, and in intrusion detection system alerts. Unfortunately, the
sheer amount of information from these sources can be overwhelming!
If your organization only has a small number of systems, it may
be feasible for a member of the system administration or security
staff to manually examine the log files of your systems. While this
is a tedious job, it is possible for small amounts of information.
Performed on a daily basis, the total amount of log entries that
needs to be examined is small.
Unfortunately, it does not take many systems to create log files
that will overwhelm someone who is looking at the log files manually.
In this case, an automated tool is required. This tool can be as
simple as a home-grown script that searches for certain types of
log entries (error messages or denials for example) or it can be
a more complex, commercial product.
Generally, what you should be looking for is something unusual.
Seeing an internal system with a large number of failed login attempts
or denials for file access may cause an investigation to find out
why this is happening. Likewise, a firewall log that shows an internal
system trying to make connections to some external connection at
odd times of day may indicate a virus infection or a Trojan Horse
program.
Do not expect the log file to tell you everything about the issue.
You will likely have to do some additional investigation to find
out exactly what is happening to cause the strange message.
Read past HIPAA / SECURE Q/A articles.
Eric Maiwald, CISSP, is Chief Technology Officer of Fortrex Technologies,
which provides information security management, and process and
monitoring services for healthcare organizations and other industries.
www.fortrex.com
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