1 How do the viruses propagate between computers 2 What is s

1. How do the viruses propagate between computers?

2. What is social engineering?

3. How will an SPI firewall handle a packet containing a TCP segment which is an acknowledgement?

4. For each of the following passwords, first state the kind of attack that would be necessary to crack it. Justify your answer. Then say whether or not it is an adequate password, again giving specific reasons.

a) password

b) Winter1

c) SpringBreaK

d) 2!T*d (00-10)

e) 9g&8tY7#?s+445=232+

please answer all questions

Solution

Answer 1: Viruses propagate in computers usually through three ways-

a. Infected Removable Media - Removable media like pendrives, hard disks, mobile devices etc. which are infected with viruses; which when plugged in to computer.

b. Email attachments - Viruses can not be transmitted through simple plain text emails. But, can spread via email attachments(like- heavy files, applications) by opening them without knowing that what the email attachment contains?

c. Downloads and applications - Downloading some softwares or files from rogue websites, may cause a flurry of popups on computer screen or download bugs to your computer. If you are on work network, and network is infected with bug or virus, then there are chances that your computer gets infected.

2. Social Engineering - It is an act by which a person is influenced or manipulated to break his normal security procedures. For example - your co-worker(attacker) wants to access additonal network resources may use social engineering tactics to gather information like passwords, ip addresses. Because it is a easier way than to dicover ways to hack softwares.

   Social Engineering attacks can be phishing(sending fraudulent emails pretended to be from legitimate email), Impersonation(pretexting as another person to gather personal information and financial data), Vishing(attacker uses a rogue IVR system to confirm information about passwords and account numbers, also called phone phishing).

3. When an SPI firewall i.e. Stateful packet inspection, a security feature included in business networks, receives a packet containing a TCP segment which is an acknowledgement, it will check a connection state table to authenticate if the packet belongs to an established connection. If it is not, then the firewall drop all the packets, preventing unsolicited connections.

4. a) Dictionary attack can be used to crack the word password. This cracking technique uses passwords from predifined list of passwords. List of passwords include all nouns and names that can be tried in a regular vocabulary. These passwords can be easily guessed.

b,c) Hybrid attack can be used to crack the words Winter1 and SpringBreaK. Hybrid attack combines the dictionary and brute-force attack. in this attack, Passwords may start with dictionary entry and tries alternative combinations like a name with first letter capitalized, or follwed by single digit, or combination of two dictionary words. These password can also be asily cracked.

d,e) These passwords are strong passwords as they contain alphanumeric characters with no simlarity. These can only be craked by encryption techniques.