Sec?

Footprinting is the technique of gathering information about computer systems and the entities they belong to.

-Wikipedia

It is one of the phase in which the attacker gathers information about the target system before starting his attack. Footprinting can expose system weaknesses and help the attacker to exploit it. For example, an attacker might use a port scanner on the remote host to learn about the open ports. Another example would be visiting the organization’s web site to look for information that might be useful.

There are many techniques that can be used during footprinting. They are explained below:

1. Ping Sweeps: pinging a range of IP addresses to find out which hosts are running.

2. TCP Scans: Using port scanners on hosts to see which services are being offered.

3. Open Source Footprinting: Finding out information such as phone numbers, addresses, performing whois queries etc.

4. Network Enumeration: Performing various queries on the whois databases found on the internet. The hacker simply queries the domain registrar to find out the information they are looking for. There are five types of queries which are listed below:

• Registrar query: This type of query gives information about the potential domains that matches the target.
• Organizational query: This query searches many different domains associated with the company.
• Domain query: This query can be used to find the company’s address, administrator and his/her phone number and the system’s DNS servers.
• Network query: This query can be used to query ARIN (American Registry for Internet Numbers) for the IP Address blocks owned by the company.
• POC query: This query can be used to find out the number of IP Addresses that a host may have.

5. DNS interrogation: Using tools such as Nslookup, Agnet to query the DNS about the target. IT also involves performing DNS Zone transfer from improperly secured, unsuspecting DNS servers.

Once the hacker has footprinted the target system, the next step is usually the enumeration of services running on the target to find out the vulnerable places to break in.

We will be discussing those in forthcoming posts…