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Threats to computers

Threats to computers. Andrew Cormack UKERNA. Daily reported attacks. Code Red (>850). Nimda (1936). Door rattling?. These numbers are from just one MAN And many probes scan thousands of hosts Millions of JANET hosts attacked every day Automated scan/compromise programs

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Threats to computers

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  1. Threats to computers Andrew Cormack UKERNA

  2. Daily reported attacks Code Red (>850) Nimda (1936)

  3. Door rattling? • These numbers are from just one MAN • And many probes scan thousands of hosts • Millions of JANET hosts attacked every day • Automated scan/compromise programs • If you’re vulnerable you will be compromised • Security by obscurity is no longer tenable

  4. What are the targets? • Random • Scripts pick random IP address ranges • Resources • Intruders like our bandwidth, disk space, CPU power • Reputation • Intruders gain kudos for compromising high-profile sites • Revenge • Has your institution upset anyone recently? • Retaliation • Has one of your (ab)users upset anyone?

  5. What can attackers do? • Read, delete, modify your data • Misuse your resources • So they aren’t available for your users • Attack others • Leaving you to take the blame • Attack you

  6. Real examples • All from JANET sites • Mostly from automated, dumb, programs • Because they can be examined • Because they (usually) only do one thing • How much more are intelligent people doing?

  7. Threats: access to information • Reading private information • Viruses actively seek out passwords and credit cards • Deleting vital information • Department lost all files for six months • Vandalism, or just removing traces? • Modifying information • Are there vulnerabilities in finance, exams, MLEs… ?

  8. Threats: abuse of resources • Software piracy • Departmental FTP server used for distribution • Pornography • University systems used to store personal collection • Site proxy used by group to access illegal material

  9. Threats: attacking others • Compromising systems • Worms attempt break-ins to anything running HTTP • Denial of Service (DoS) • Compromised machines join flooding networks • Viruses now carry these tools • Real-world crimes • Stolen credit card numbers used for purchases • Blackmail, defamation, incitement, stalking, …

  10. Threats: attacking you • DoS attacks take sites off network • Attacker with control of system is “inside” • Attack other systems • Read traffic on networks • Disrupt service • Firewall protection failed • Social engineering attacks

  11. Some good news • Attacking is not rocket science • Nor is defending • Most successful attacks are preventable • Well-publicised vulnerabilities • Software fixes freely available • Simple toolkit • Network configuration • Patches

  12. What can you do? • Crime prevention • Reduce open windows • Limit direct access from the Internet • Fit locks • Secure hosts that are exposed or critical • Guidelines and tools exist • Use them and make sure others do

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