- How does the attack begin ?
Attackers follow a fixed methodology to penetrate into a system. The steps a hacker follows can be broadly divided into five phases:
1. Reconnaissance:
Reconnaissance or Footprinting is consideredthe first pre-attack phase and is a systematic attempt to locate, gather, identify, and record information about the target. The hacker seeks to find out as much information as possible about the victim. Some hackers might dumpster dive to find out more about the victim. Dumpster diving is the act of going through the victim's trash. Another favorite of the hacker is social engineering. A social engineer is a person who can smooth talk other individuals into revealing sensitive information. This might be accomplished by calling the help desk and asking someone to reset a password or by sending an email to an insider telling him he needs to reset an account.
2. Scanning:
Scanning and enumeration is considered the second pre-attack phase. Scanning is the active step of attempting to connect to systems to elicit a response. Enumeration is used to gather more in-depth information about the target, such as open shares and user account information. At this step in the methodology, the hacker is moving from passive information gathering to active information gathering. Hackers begin injecting packets into the network and might start using scanning tools such as Nmap. The goal is to map open ports and applications. Unlike the elite blackhat hacker who attempts to remain stealth, script kiddies might even use vulnerability scanners such as Nessus to scan a victim's network.
3. Gaining Access:
As far as potential damage, this could be considered one of the most important steps of an attack. This phase of the attack occurs when the hacker moves from simply probing the network to actually attacking it. After the hacker has gained access, he can begin to move from system to system, spreading his damage as he progresses. Access can be achieved in many different ways. A hacker might find a vulnerability in the web server's software or might perform a denial of service (DOS) on that server. If the hacker is really bold, he might even walk in and tell the receptionist that he is late for a meeting and will wait in the conference room with network access. Pity the poor receptionist who unknowingly provided network access to a malicious hacker.
4. Maintaining Access:
Hackers are diligent at working on ways to maintain access to the systems they have attacked and compromised. They might attempt to pull down the etc/passwd file or steal other passwords so that they can access other user's accounts. Rootkits are one option for hackers. A rootkit is a set of tools used to help the attacker maintain his access to the system and use it for malicious purposes.
5. Clearing Tracks:
Nothing happens in a void, and that includes computer crime. Hackers are much like other criminals in that they would like to be sure to remove all evidence of their activities. Hackers must also be worried about the files or programs they leave on the compromised system. In order that the target company’s security engineer or network administrator cannot detect the evidence of attack, the hacker needs to delete logs files and replace system binaries with Trojans.
- How do you defend the attack ?
In order to defend a hacker, you have to think from his/her perspective. Being an ethical hacker, you will need to be aware of these tools and techniques to discover their activities and to deploy adequate countermeasures.
