Rootkits are pieces of software that are specifically designed to give the person who deploys them control of the target computer. They achieve this by either infecting programs used by the user, the operating system, boot records, or the computer system’s firmware. This, in addition to the fact that it employs misdirection and other advanced techniques to avoid detection by antivirus software, increases its potential for damaging your Mac computer.
Therefore, if your computer system is acting up for no apparent reason, and if your system’s antivirus cannot locate the source of the problem despite its best efforts, chances are that a rootkit infection is to blame. Here is what you should know about rootkits, how they try to conceal themselves, and how you can detect them.
How Rootkits Conceal Themselves?
A unique characteristic of a rootkit is its resolve to go undetected. Once it infects a system as a result of any kind of security vulnerability, it seeks to ensure that both its presence and its activities go undetected, it employs a number of clever strategies.
If your computer slows down, an easy way to tell whether there are applications that are devouring your resources is to simply ask for a list of active programs. Using this method, it is easy to catch most malicious programs. However, this is rarely enough to detect a rootkit. This is because it can delete any programs it is running from such a list and hence guaranteeing that it will go undetected.
A rootkit can also avoid detection by using different file names or names that are like existing programs. It can alter legitimate files or sometimes even replace them entirely. To make it harder to detect, it can also intercept calls that are being made to libraries. In such a case, for as long as these libraries are not compiled statically, the rootkit can always avoid detection by “answering” the call with misleading information.
Kernel rootkits are even harder to detect because of the high level of access that they enjoy. With these rootkits, they easily go undetected because they can change the type of calls that the operating system and the way it functions. As a result of its advanced privileges, it can easily fool antivirus software by providing it with falsified information that hides its presence.
Rootkits that infect a system’s boot records can also evade detection by deactivating the defense mechanisms of the operating system and other antivirus programs before they even have a chance to begin running. Doing so allows them to operate without raising alarm simply because they have already compromised the systems that are supposed to raise such an alarm.
How to Detect Rootkits
Your System Starts Acting Up
A slow computer is a common sign of rootkit infection. This is so mainly because, to execute any malicious code, the rootkit will have to use your computer resources. As a result, this is a common sign of rootkits like memory rootkits.
However, since most malware can slow down the computer system, you should start suspecting a rootkit if it is accompanied by frequent problems like increased blue screen encounters. A generally unstable system that crashes often is also an indication of a rootkit infection, since these programs are the ones that typically have system-level access that is deep enough to destabilize the entire system.
Signatures and Analysis of Unusual Events
Known rootkits have a pattern of behavior. They may delete a given set of files or launch an attack in a unique way. Based on the distinguishing characteristics of how the rootkit acts or how it tries to conceal itself, a good antivirus for Mac can detect its presence. It will have to have an updated database to be effective, and in most cases, this is enough to detect basic rootkits.
File Integrity Checks
File integrity checks are effective at detecting signs user mode rootkits. Tools that are designed to run these checks usually start off by creating an inventory and then compiling each system file’s hash. After this data is stored in a database, the tool then runs a test of the system and the results are then compared with what exists in the database. Any differences in the comparison could then indicate an infection.
Dedicated Rootkit Tools
Instead of looking for the rootkit in an environment where it has complete control and where it can hide effectively by intercepting calls, some tools opt to use neutral ground. They achieve this by launching the computer on a CD or any other separate storage space and then observe how the system behaves. Doing this also nullifies the common concealment and obfuscation techniques that the rootkit might have employed. This makes it easier to both detect and delete the rootkit.