In which cloud crime do attackers try to compromise the security of the cloud environment in order to steal data or inject a malware?

Which of the following should a computer forensics lab used for investigations have?

Heather, a computer forensics investigator, is assisting a group of investigators working on a large computer fraud case involving over 20 people. These 20 people, working in different offices, allegedly siphoned off money from many different client accounts. Heather responsibility is to find out how the accused people communicated between each other. She has searched their email and their computers and has not found any useful evidence. Heather then finds some possibly useful evidence under the desk of one of the accused.
In an envelope she finds a piece of plastic with numerous holes cut out of it. Heather then finds the same exact piece of plastic with holes at many of the other accused peoples desks. Heather believes that the 20 people involved in the case were using a cipher to send secret messages in between each other. What type of cipher was used by the accused in this case?

The Apache server saves diagnostic information and error messages that it encounters while processing requests. The default path of this file is usr/local/apache/logs/error.log in Linux. Identify the Apache error log from the following logs.

What is a good security method to prevent unauthorized users from "tailgating"?