INF4831 INFORMATION SECURITY QUESTIONS AND ANSWERS
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Intrusions
An attempt to gain unauthorised access to your system
Malware
Automated attacks designed to exploit common vulnerabilities
Denial of Service attacks (DoS)
Deny's authorised users access to the system.
UDP Flood, TCP SYN Flood, ICMP Flood, Smurf IP attack.
Nuke Attack: Tie computer up.
Vulnerabilities
Mistakes in programs that allow bad things to happen
Biggest vulnerability: USERS
Cross site scripting, Cross site request forgery, cookie injection
Network vulnerabilities
Man in the middle attacks, Router attacks, Ethernet traffic sniffing, DNS attacks
Secure Socket Layer (SSL)
Secure communication method which protects web traffic
Perimeter Security
Nothing leaves unless explicitly authorized. All information is checked at perimeter.
Used in contexts where any leaked information is bad. Government, Military. Expensive
and complex.
Layered Security
Most sensitive information is accessed by the least number of people. Internal access
controls are placed on data. Cheaper and simpler than perimeter security. Widely used
in business
Attacking the Network Methodology
1. Footprint
2. Scan
3. Enumerate
4. Penetrate
5. Attack
6. Cover Tracks
7. Install back doors
Reconnaissance
Footprint, Scan and Enumerate. Aim is to find attack vectors
Attack Vectors
parts of the application that can be reached by users. All attack vectors form the attack
surface
Footprinting
, Gathering information about the target. IP addresses, web presence, phone numbers,
emails
Footprinting questions
What software is the target based on? What language does the target use? How can
you communicate with the target?
Footprinting Tools
who.is, nslookup, social engineering
Scanning
determines which of the systems are net accessible . which IP addresses are
accessible, any obvious open doors. At its most basic, ping and address to see if its
alive, scan the ports to see if they are open. Google the port numbers to get application,
google the applications to get vulnerabilities
FIN Scanning
If port is in LISTEN, no reply.
If port is closed, responds with reset.
SYN Scanning
if port is open, responds with SYN/ACK.
you return RESET, no connection established.
Sneaky manipulation of TCP
Send TCP FIN packet, if the port is in LISTEN, no reply. if the port is in CLOSED,
responds with reset. no connection attempt made. Send a SYN packet, if port is open,
responds with SYN/ACK. You return RESET, no connection.
Dorking
using advanced google searches to reveal vulnerable websites
Shodan
Device search engines. Permits searching by IP address, open port, Active protocol,
Vulnerability number
Enumeration
The process of identifying low hanging fruit and user accounts. Scanning shows you the
doors, enumeration identifies how to get through them safely.
Spidering
Automated mapping of websites or file system. Program that recursively follows all links
in a HTML document. can reveal old insecure pages, backups, databases connected
etc.
Penetration
Entering the system using information discovered up till now
Attacking
the attacker accomplishes their goal
Covering Tracks
inexperienced attacker leaves evidence. Turn off event logging, clearing event logs,
hide malicious files left behind.
Installing back doors
intruder installs back door to make intrusions easier
Attacking a web server
1. identify all entry points
2. examine the structure of entry points
A+ GRADED. Buy Quality Materials!
Intrusions
An attempt to gain unauthorised access to your system
Malware
Automated attacks designed to exploit common vulnerabilities
Denial of Service attacks (DoS)
Deny's authorised users access to the system.
UDP Flood, TCP SYN Flood, ICMP Flood, Smurf IP attack.
Nuke Attack: Tie computer up.
Vulnerabilities
Mistakes in programs that allow bad things to happen
Biggest vulnerability: USERS
Cross site scripting, Cross site request forgery, cookie injection
Network vulnerabilities
Man in the middle attacks, Router attacks, Ethernet traffic sniffing, DNS attacks
Secure Socket Layer (SSL)
Secure communication method which protects web traffic
Perimeter Security
Nothing leaves unless explicitly authorized. All information is checked at perimeter.
Used in contexts where any leaked information is bad. Government, Military. Expensive
and complex.
Layered Security
Most sensitive information is accessed by the least number of people. Internal access
controls are placed on data. Cheaper and simpler than perimeter security. Widely used
in business
Attacking the Network Methodology
1. Footprint
2. Scan
3. Enumerate
4. Penetrate
5. Attack
6. Cover Tracks
7. Install back doors
Reconnaissance
Footprint, Scan and Enumerate. Aim is to find attack vectors
Attack Vectors
parts of the application that can be reached by users. All attack vectors form the attack
surface
Footprinting
, Gathering information about the target. IP addresses, web presence, phone numbers,
emails
Footprinting questions
What software is the target based on? What language does the target use? How can
you communicate with the target?
Footprinting Tools
who.is, nslookup, social engineering
Scanning
determines which of the systems are net accessible . which IP addresses are
accessible, any obvious open doors. At its most basic, ping and address to see if its
alive, scan the ports to see if they are open. Google the port numbers to get application,
google the applications to get vulnerabilities
FIN Scanning
If port is in LISTEN, no reply.
If port is closed, responds with reset.
SYN Scanning
if port is open, responds with SYN/ACK.
you return RESET, no connection established.
Sneaky manipulation of TCP
Send TCP FIN packet, if the port is in LISTEN, no reply. if the port is in CLOSED,
responds with reset. no connection attempt made. Send a SYN packet, if port is open,
responds with SYN/ACK. You return RESET, no connection.
Dorking
using advanced google searches to reveal vulnerable websites
Shodan
Device search engines. Permits searching by IP address, open port, Active protocol,
Vulnerability number
Enumeration
The process of identifying low hanging fruit and user accounts. Scanning shows you the
doors, enumeration identifies how to get through them safely.
Spidering
Automated mapping of websites or file system. Program that recursively follows all links
in a HTML document. can reveal old insecure pages, backups, databases connected
etc.
Penetration
Entering the system using information discovered up till now
Attacking
the attacker accomplishes their goal
Covering Tracks
inexperienced attacker leaves evidence. Turn off event logging, clearing event logs,
hide malicious files left behind.
Installing back doors
intruder installs back door to make intrusions easier
Attacking a web server
1. identify all entry points
2. examine the structure of entry points
