The rising volume of "denial of service" attacks by hackers may actually represent good news for users, according to a computer security specialist.
Hackers blocking outside access to sites by tricks such as flooding network links with traffic may be doing it because penetrating inside systems is becoming harder, suggested Auscert operations manager Danny Smith. Smith is giving a series of seminars around Australia on computer security trends.
Disrupting user access has long been a standard item on the hacker menu, but the trend has been increasing in recent months, Smith says. One reason for the increase is the appearance of improved tools and techniques for launching denial attacks. They allow hackers to identifiy potential chokepoints where fast networks connect to slower ones, then flood the link from the high-bandwidth side.
Another ploy is to deliberately make a number of failed log-in attempts and provoke the password program into locking the account even against legitimate users.
In terms of security threats, denial-of-service attacks are probably preferable to system penetration efforts. "It has crossed my mind that this could mean hackers are getting frustrated with better defences," Smith says. It doesn't mean network administrators should relax their efforts in other areas, he says.
In particular, good password enforcement mechanisms are still vital, with users requiring continued education reinforced by gentle hints such as screening new password registrations and rejecting obviously inadequate choices.
"One of the things that needs highlighting is that solutions already exist for 99% of the cases of people who come to us because their systems have been broken into. They have known problems with known solutions and education is the key to avoiding the problem in the first place."
Firewalls at best "buy time to hold the wolves at bay while you fix up the vulnerabilities in your systems," Smith says.
"Too many people use it to shield the vulnerabilities, then don't bother to repair those weak spots."
That attitude makes it only a matter of time before hackers "break through the hard shell and start on the soft, chewy centre," Smith says.