Explanation: If Incident Handling is underway an incident has potentially been identified. At that point all use of the system should stop because the system can no longer be trusted and any changes could contaminate the evidence. This would include all System Development Activity.
Every organization should have plans and procedures in place that deals with Incident Handling.
Employees should be instructed what steps are to be taken as soon as an incident occurs and how to report it. It is important that all parties involved are aware of these steps to protect not only any possible evidence but also to prevent any additional harm.
It is quite possible that the fraudster has planted malicous code that could cause destruction or even a Trojan Horse with a back door into the system. As soon as an incident has been identified the system can no longer be trusted and all use of the system should cease.
Shon Harris in her latest book mentions:
Although we commonly use the terms “event” and “incident” interchangeably, there are subtle differences between the two. An event is a negative occurrence that can be observed, verified, and documented, whereas an incident is a series of events that negatively affects the company and/ or impacts its security posture. This is why we call reacting to these issues “incident response” (or “incident handling”), because something is negatively affecting the company and causing a security breach.
Many types of incidents (virus, insider attack, terrorist attacks, and so on) exist, and sometimes it is just human error. Indeed, many incident response individuals have received a frantic call in the middle of the night because a system is acting “weird.” The reasons could be that a deployed patch broke something, someone misconfigured a device, or the administrator just learned a new scripting language and rolled out some code that caused mayhem and confusion.
When a company endures a computer crime, it should leave the environment and evidence unaltered and contact whomever has been delegated to investigate these types of situations. Someone who is unfamiliar with the proper process of collecting data and evidence from a crime scene could instead destroy that evidence, and thus all hope of prosecuting individuals, and achieving a conviction would be lost.
Companies should have procedures for many issues in computer security such as enforcement procedures, disaster recovery and continuity procedures, and backup procedures. It is also necessary to have a procedure for dealing with computer incidents because they have become an increasingly important issue of today’s information security departments. This is a direct result of attacks against networks and information systems increasing annually. Even though we don’t have specific numbers due to a lack of universal reporting and reporting in general, it is clear that the volume of attacks is increasing.
Just think about all the spam, phishing scams, malware, distributed denial-of-service, and other attacks you see on your own network and hear about in the news. Unfortunately, many companies are at a loss as to who to call or what to do right after they have been the victim of a cybercrime. Therefore, all companies should have an incident response policy that indicates who has the authority to initiate an incident response, with supporting procedures set up before an incident takes place.
This policy should be managed by the legal department and security department. They need to work together to make sure the technical security issues are covered and the legal issues that surround criminal activities are properly dealt with. The incident response policy should be clear and concise. For example, it should indicate if systems can be taken offline to try to save evidence or if systems have to continue functioning at the risk of destroying evidence. Each system and functionality should have a priority assigned to it. For instance, if the file server is infected, it should be removed from the network, but not shut down. However, if the mail server is infected, it should not be removed from the network or shut down because of the priority the company attributes to the mail server over the file server. Tradeoffs and decisions will have to be made, but it is better to think through these issues before the situation occurs, because better logic is usually possible before a crisis, when there’s less emotion and chaos.
The Australian Computer Emergency Response Team’s General Guidelines for Computer Forensics:
Keep the handling and corruption of original data to a minimum.
Document all actions and explain changes.
Follow the Five Rules for Evidence (Admissible, Authentic, Complete, Accurate, Convincing).
• Bring in more experienced help when handling and/ or analyzing the evidence is beyond your knowledge, skills, or abilities.
Adhere to your organization’s security policy and obtain written permission to conduct a forensics investigation.
Capture as accurate an image of the system( s) as possible while working quickly.
Be ready to testify in a court of law.
Make certain your actions are repeatable.
Prioritize your actions, beginning with volatile and proceeding to persistent evidence.
Do not run any programs on the system( s) that are potential evidence.
Act ethically and in good faith while conducting a forensics investigation, and do not attempt to do any harm.
The following answers are incorrect:
help-desk function. Is incorrect because during an incident, employees need to be able to communicate with a central source. It is most likely that would be the help-desk. Also the help-desk would need to be able to communicate with the employees to keep them informed.
system imaging. Is incorrect because once an incident has occured you should perform a capture of evidence starting with the most volatile data and imaging would be doen using bit for bit copy of storage medias to protect the evidence.
risk management process. Is incorrect because incident handling is part of risk management, and should continue.
Reference(s) used for this question:
Harris, Shon (2012-10-25). CISSP All-in-One Exam Guide, 6th Edition (Kindle Locations 21468-21476). McGraw-Hill. Kindle Edition.
and
Harris, Shon (2012-10-25). CISSP All-in-One Exam Guide, 6th Edition (Kindle Locations 21096-21121). McGraw-Hill. Kindle Edition.
and
NIST Computer Security incident handling http://csrc.nist.gov/publications/nistpubs/800-12/800-12-html/chapter12.html
