1. Intro to Network Security
Politeknik Elektronika Negeri Surabaya
2007
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2. Introduction Penilaian Max terlambat 15 menit dari pelajaran dimulai
Tugas 25%
UAS 40%
UTS 30%
Kehadiran 5%
Max terlambat 15 menit dari pelajaran dimulai
Di atas 15 menit diberi tugas dan dipresentasikan
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3. Overview
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4. Network Services DMZ INTERNET PENS-ITS ROUTER GTW FIREWALL EIS
CISCO Router
Using acl ,
block malware
from outside
INTERNET
NOC
MULTILAYER
SWITCH
ROUTER
All Server in DMZ
GTW
Manage using SSH , -
Secure Webmin
FIREWALL
FIREWALL -
IDS
PROXY (
Squid )
Linux bridge ,
iptables
All access to Internet
must through Proxy
shorewall ,
snort ,
Managable Switchs
DMZ
portsentry ,
acidlab
Block unwanted user from port ,
manage from WEB
SQL Database (
MySQL )
Access only from
localhost (
127 . . . 1 )
EIS
WWW
DOMAIN L 3
Switch
Block malware on
physical port from inside
LECTURER
network
EMPLOYEE E -
MAIL ,
PROXY
Traffic Monitoring
CACTI
Http
://
noc .
eepis -
its .
edu E -
Mail server
HTTPS ,
SPAM
EEPISHOTSPOT (
Spamassassin ) ,
Virus
Access from wifi ,
signal
Scanner (
ClamAV )
only in EEPIS campus
Authentication from
Proxy
FILESERVER
STUDENTS
Internal Server
EEPIS -
INFORMATION SYSTEM
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EIS http
://
eis .
eepis -
its .
edu )
EEPISHOTSPOT
Http
://
fileserver .
eepis -
its .
edu

5. Incorrect permissions
Why Secure a Network?
Internal attacker
External attacker
Corporate Assets
Incorrect permissions
Virus
A network security design protects assets from threats and vulnerabilities in an organized manner
To design security, analyze risks to your assets and create responses
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6. Computer Security Principles
Confidentiality
Protecting information from exposure and disclosure
Integrity
Decrease possible problems caused by corruption of data
Availability
Make information always available
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7. Exploits (1) What is an Exploit? Types of attacks
Crackers break into a computer network by exploiting weaknesses in operating system services.
Types of attacks
Local
Remote
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8. SANS Security Threats SANS/FBI top 20 security threats
Goals attackers try to achieve
Gain unauthorized access
Obtain administrative or root level
Destroy vital data
Deny legitimate users service
Individual selfish goals
Criminal intent
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9. Security Statistics: Attack Trends
Computer Security Institute (
Growing Incident Frequency
Incidents reported to the Computer Emergency Response Team/Coordination Center
1997: 2,134
1998: 3,474 (75% growth from previous year)
1999: 9,859 (164% growth)
2000: 21,756 (121% growth)
2001: 52,658 (142% growth)
Tomorrow?
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10. Attack Targets SecurityFocus 31 million Windows-specific attacks
22 million UNIX/LINUX attacks
7 million Cisco IOS attacks
All operating systems are attacked!
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11. Hackers Vs Crackers Ethical Hackers vs. Crackers
Hacker usually is a programmer constantly seeks further knowledge, freely share what they have discovered, and never intentionally damage data.
Cracker breaks into or otherwise violates system integrity with malicious intent. They destroy vital data or cause problems for their targets.
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12. Pengelompokan Attack
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13. Pengelompokan Attacks
Physical Access
Attacks --
Wiretapping/menyadap
Server Hacking
Vandalism/perusakan
Social Engineering --
Opening Attachments
Password Theft
Information Theft
Dialog Attacks --
Eavesdropping
(Mendengar yg tdk boleh)
Impersonation
(meniru)
Message Alteration
Merubah message
Penetration
Attacks
(Usaha menembus)
Malware --
Viruses
Worms
Denial of
Service
Break-in
Scanning
(Probing)
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14. Social Engineering Definisi Social enginering
seni dan ilmu memaksa orang untuk memenuhi harapan anda ( Bernz ),
Suatu pemanfaatan trik-trik psikologis hacker luar pada seorang user legitimate dari sebuah sistem komputer (Palumbo)
Mendapatkan informasi yang diperlukan (misalnya sebuah password) dari seseorang daripada merusak sebuah sistem (Berg).
Tujuan dasar social engineering sama seperti umumnya hacking: mendapatkan akses tidak resmi pada sistem atau informasi untuk melakukan penipuan, intrusi jaringan, mata-mata industrial, pencurian identitas, atau secara sederhana untuk mengganggu sistem atau jaringan.
Target-target tipikal termasuk perusahaan telepon dan jasa-jasa pemberian jawaban, perusahaan dan lembaga keuangan dengan nama besar, badan-badan militer dan pemerintah dan rumah sakit.
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15. Bentuk Social Engineering
Social Engineering dengan telepon
Seorang hacker akan menelpon dan meniru seseorang dalam suatu kedudukan berwenang atau yang relevan dan secara gradual menarik informasi dari user.
Diving Dumpster
Sejumlah informasi yang sangat besar bisa dikumpulkan melalui company Dumpster.
Social engineering on-line :
Internet adalah lahan subur bagi para teknisi sosiaal yang ingin mendapatkan password
Berpura-pura menjadi administrator jaringan, mengirimkan melalui jaringan dan meminta password seorang user.
Persuasi
Sasaran utamanya adalah untuk meyakinkan orang untuk memberikan informasi yang sensitif
Reverse social engineering
sabotase, iklan, dan assisting
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16. Penetration Attacks Steps
Port scanner
Network enumeration
Gaining & keeping root / administrator access
Using access and/or information gained
Leaving backdoor
Attack
Denial of Services (DoS) :Network flooding
Buffer overflows : Software error
Malware :Virus, worm, trojan horse
Brute force
Covering his tracks
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17. Scanning (Probing) Attacks
Reply from
Probe Packets to
, , etc.
Host
Internet
Attacker
No Host
Results
is reachable
is not reachable …
No Reply
Corporate Network
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18. Network Scanning
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19. Denial-of-Service (DoS) Flooding Attack
Message Flood
Server
Overloaded By
Message Flood
Attacker
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20. DoS By Example
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21. Dialog Attack
Eavesdropping, biasa disebut dengan spoofing, cara penanganan dengan Encryption
Impersonation dan message alteration ditangani dengan gabungan enkripsi dan autentikasi
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22. Eavesdropping on a Dialog
Hello
Client PC
Bob
Server
Alice
Hello
Attacker (Eve) intercepts
and reads messages
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23. Password Attack By Example
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24. Sniffing By Example
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25. KeyLogger
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26. Attacker (Eve) intercepts
Message Alteration
Dialog
Client PC
Bob
Balance =
$1,000,000
Balance = $1
Server
Alice
Balance = $1
Balance =
$1,000,000
Attacker (Eve) intercepts
and alters messages
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27. PENS-ITS

28. Security form Attack
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29. Network Penetration Attacks and Firewalls
Passed Packet
Attack
Packet
Internet
Firewall
Hardened
Client PC
Internet
Attacker
Hardened
Server
Dropped
Packet
Internal
Corporate
Network
Log File
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30. Intrusion Detection System1.
Suspicious
Packet
4. Alarm
Intrusion
Detection
System
Network
Administrator
2. Suspicious
Packet Passed
Internet
Attacker
Hardened
Server
3. Log
Packet
Log File
Corporate Network
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31. Encryption for Confidentiality
Encrypted
Message
“ ”
Client PC
Bob
Server
Alice
“ ”
Attacker (Eve) intercepts
but cannot read
Original
Message
“Hello”
Decrypted
Message
“Hello”
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32. Impersonation and Authentication
I’m Bob
Client PC
Bob
Prove it!
(Authenticate Yourself)
Attacker
(Eve)
Server
Alice
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33. Secure Dialog System Secure Dialog Client PC Bob Automatically Handles
Negation of Security Options
Authentication
Encryption
Integrity
Server
Alice
Attacker cannot
read messages, alter
messages, or impersonate
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34. Hardening Host Computers
The Problem
Computers installed out of the box have known vulnerabilities
Not just Windows computers
Hackers can take them over easily
They must be hardened—a complex process that involves many actions
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35. Hardening Host Computers
Elements of Hardening
Physical security
Secure installation and configuration
Fix known vulnerabilities
Turn off unnecessary services (applications)
Harden all remaining applications (Chapter 9)
(more on next page)
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36. Hardening Host Computers
Elements of Hardening (continued)
Manage users and groups
Manage access permissions
For individual files and directories, assign access permissions specific users and groups
Back up the server regularly
Advanced protections
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37. Hardening Host Computers
Security Baselines Guide the Hardening Effort
Specifications for how hardening should be done
Different for different operating systems
Different for different types of servers (webservers, mail servers, etc.)
Needed because it is easy to forget a step
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38. Installation and Patching
Installation Offers Many Options, Some of Which Affect Security
For example, in Windows, the NTFS file system is better for security than FAT32
Need a security baseline to guide option choices during installation
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39. Installation and Patching
Known Vulnerabilities
Most programs have known vulnerabilities
Exploits are programs that take advantage of known vulnerabilities
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40. Installation and Patching
Known Vulnerabilities
Vulnerability reporters send vulnerability reports to vendors
Vulnerability reporters often say that vendors take too long to fix vulnerabilities
Vendors say that vulnerability reporters do not give them enough time, report too much detail to the press
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41. Installation and Patching
Fixes
Work-around: A series of actions to be taken; no new software
Patches: New software to be added to the operating system
Upgrades: Newer versions of programs usually fix older vulnerabilities.
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42. Installation and Patching
Upgrades
Often, security vulnerabilities are fixed in new versions
If a version is too old, the vendor might stop offering fixes
It might be good to wait to upgrade until after the first round of bug and security fixes
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43. Turning Off Unnecessary Services
Operating system vendors used to install many services by default
This made them easier to use. When use changes, services do not have to be turned on.
Attackers have found flaws in many of these rare services
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44. Turning Off Unnecessary Services
Vendors now install fewer services by default— lock down mode
Turn to security baseline to see what services to turn on and off
Easier to install too few and add than to install too many and remove unwanted services
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45. Managing Users and Groups
Introduction
Every user must have an account
There can also be groups
Can assign security measures to groups
These measures apply to the individual group members automatically
Faster and easier than assigning security measures to individuals
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46. Managing Permissions
Principle of Least Permissions: Give Users the Minimum Permissions Needed for Their Job
More feasible to add permissions selectively than to start with many, reduce for security
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47. Advanced Server Hardening Techniques
Reading Event Logs
The importance of logging to diagnose problems
Failed logins, changing permissions, starting programs, kernel messages, etc.
Backup
File Encryption
File Integrity Checker
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