This document discusses various computer network attacks and vulnerabilities. It covers topics like ransomware, IoT attacks, social engineering, man-in-the-middle attacks, denial of service attacks, distributed denial of service attacks, SQL injection, SSL stripping, URL misinterpretation, directory browsing, input validation vulnerabilities, and vulnerabilities in each layer of the OSI model. The goal is to provide an overview of common network attacks and how they can be carried out.

1. Case Study on
COMPUTER NETWORKS
SHIVAM BAJAJ

2. When You have Network , You have given Access of your Social Life to that Network .

3. Top Network Attacks
• Ransomware - Attackers manages to get a malicious file onto
your servers with the use form of phishing . Using phishing
keystroke logging files also managed .
• IOT - It is a growing field . no. of devices are increasing and
attack on that can cause chaos on enormous scale due to
unsecured digital devices or old protocols used .
• Social Engineering - It implies deceiving someone with
purpose of acquire sensitive information , like passwords ,
credit cards . Clone Phishing is used in this
• MIM Attacks - Session Hijacking . Spoofing .

4. • DOS - Denial of service attack , it is malicious attempt to
make a server or network resource unavailable to users ,
usually by suspending the services of hosts .
• DDOS - Distributed Denial of Service Attack
• SQL Injection - It is an SQL code injection technique ,
used to attack data driven app , in which malicious queries
are inserted into entry field for execution .

5. Typical Web Application Set Up

6. • SSL(Secure Sockets Layer ) is protocol for establishing
encrypted links b/w server and browser .
• It is the predecessor to TLS .
• When server return pages with https links , attacker
changes them to http and when browser uses links , MITM
intercepts and creates its own https con with server
• Result MITM sees all the packets in that network .
• Using nectar and OpenSSL , 2 line proxy can be created .
• listen on 80 port on host and redirect requests to port 443.
SSL Stripping

7. • URL Misinterpretation - Web servers fails to parse the
URL properly . eg - Unicode/ Superflous decode attack .
• Directory Browsing - ability to retrieve complete directory
listing within directories on web server . usually happens
when default document is missing .
• Reverse proxy server - proxy that typically sits behind the
firewall in private network and direct client to backend
server and provides an additional level of abstraction .
eg Compaq Insight manager .
• Java Decompilation - Java Byte code can be decompiled
quite effectively and disclose sensitive info like password.

8. • Source Code Disclosure - Ability to retrieve app files in
unparsed manner and can recover code . the code then
can be used to find further loopholes/trophies.
• Input Validation - Root cause of most web attacks .
Tampering with hidden fields , Bypassing client side
checking eg javascript .
• Butter Overflows - flaw that occurs when more data is
written to buffer , can cause DOS . Application Input Fields
eg - ColdFusion Dos .
• Fragrouter - network intrusion detection evasion toolkit . It
implements Insertion , Evasion and DOS attack .

9. Vulnerabilities in Layers of
OSI Model .

10. • Physical Layer - Physical destruction , obstruction ,
manipulation or malfunction of physical assets .
• Data Link layer - Mac flooding attack inmates switch with
data packets .
• Network Layer - ICMP flooding , attacker uses ICMP
messages to overload targeted network’s bandwidth .
• Transport Layer - SYN Flood , Smurf attack .
• Session Layer - attacker exploits a flaw in server software
running on switch,rendering telnet services unavailable .
• Presentation Layer - SSL stripping & Malformed SSL
requests , to tunnel HTTP attacks to the target server .
• Application Layer - DDos attack .Get requests , HTTP GET
HTTP Post , = website forms .