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What Is Malware? How to Look for It and Protect Your Assets

19 de Enero de 2021
por Sagar Joshi

Malware, and other web-based threats that put your assets at risk, can inevitably cause more damage than you imagined.

Malware can make trained security professionals go berserk during security incidents and take a toll on your finances and reputation when you run a business. It’s essential to have proper preventative measures set before malware can infest your security framework. 

But if the attack actually converges on your system or network, you’ll need a proper plan to respond and incident response tools to execute the response plan effectively.

Malware can infect your computer majorly by tricking you into opening a malicious link or installing a program or software from an untrusted source. Generally, it’s delivered through phishing attempts, a social engineering attack where hackers send malware embedded inside attachments disguised as a normal file.

Malware can steal, encrypt, modify, or delete your data depending on its type. Sometimes, it can hijack your computer’s core functions, and feed on battery and network speed, and other computational resources where it confirms its presence.

It’s in your best interest to study such signals carefully to detect the presence of a malicious program in your system or network.

How does malware work?

Simply put, different types of malware work differently. Every one of them has peculiarities in the nature of damage it causes to the user or their organization. Let’s dive deeper into the different types of malware and get a comprehensive understanding of the ways it can affect your devices.

Viruses

This type of malware needs an infected and active operating system or program run. It’s a part of an executable file, which, when run, enables the virus to cause damage and infect other files. 

Normally, it creates a challenge for the antivirus program to contain or remove it exclusively as it’s a part of the program. The antivirus software isolates the infected file or deletes it permanently to limit its damage and contain the spread.

You could be welcoming a virus when you download software from untrusted sources or fall victim to a phishing attempt that tricks you into downloading an executable file.

There are two types of viruses are follows:

  • Compiled virus: These viruses are executed by an operating system (OS). A file infector virus that attaches itself to an executable file or boot sector virus that infects the master boot records of hard drives or removable media is its sub-categories. The compiled virus also comprises the multipartite virus, which is a combination of a file infector virus and boot sector virus.
  • Interpreted virus: These viruses are executed by a particular application. These have been further divided into two subcategories – macro and scripting viruses. Macro leverages the macro programming language of the application to infect files and documents, whereas scripting viruses infect scripts that are interpreted by specific services on the operating system.

Worms

Worms are malicious programs that spread through vulnerabilities in software or through phishing attempts. Once you’re infected with a worm, it starts spreading through your system and also sometimes over the network.

Worms are divided into two subcategories:

  • Network service worm: These infect host systems by exploiting a vulnerability in the network service to propagate.
  • Mass mailing worm: These spread through emails in phishing attempts, but unlike viruses, they are self-contained.

Worms can consume your bandwidth and can spread over a large number of computers quickly, overloading the web servers. These are self-contained and can execute themselves without any human intervention.

Adware

Adware is unwanted software that is programmed to display ads on your screen, usually in a web browser. This type of malware disguises itself as a legitimate software program to trick you into downloading and installing it on your computer.

It might display a message like “you have won a lifetime membership of XYZ software,” or any other in a similar context, positioned to benefit you. Behind a false pretense of a genuine offer, discount, or prize, adware plays you into fulfilling the ulterior motives of the attacker and puts your device at risk.

Another way how adware works is by exploiting an exposed vulnerability in your web browser that allows drive-by download, which refers to the unintended download of more than one file that may be malicious or may not be.

Bots

Bots are programs that automatically execute tasks as ordered by the creator of the program that has infected them. The most common malicious uses of bots are in DDoS attacks, where huge numbers of bots (botnets) are deployed to attack servers.

Bots can be grouped together once infected with malware and their collective computing power used as a botnet to carry out the hacker’s desired tasks.

Rootkits

A rootkit is a set of software tools that provide unauthorized access to a user while staying actively hidden. Once installed on a system, a rootkit can help an attacker gain remote access to the files and information stored on a device while modifying configurations on the host.

With the help of rootkit, an attacker can also view log files and secretly spy on a device user’s activities. To detect a rootkit, you can examine the computer for strange behavior or use other methods of detection, like signature scanning and memory dump analysis.

Using rootkits, attackers can enter your system by piggybacking on the software you trust or with a virus. To protect your system against them, ensure that vulnerabilities in your operating system and applications are properly patched. Also, it's important that your antivirus software is up to date with the current, updated database of new viruses. Often, the only method of removing a rootkit is to rebuild the compromised system.

Spyware

Spyware is malicious software designed to infiltrate your computing device and steal data related to your internet usage and other sensitive information you may keep on a device. Usually a spyware program conspires to sell your internet usage statistics, bank account information, or other personally identifiable information on the black market.

Spyware may penetrate your system in the form of adware or trojan, where the program displays your ads (pretending to be genuine) based on your internet usage. On the other hand, it may come as malicious software disguised as a flash player update or the like.

There are spyware programs that can capture everything that’s going on in your computing device. Some may even track cookies to access your browsing history and activities to offer you the perfect bait and allow attackers to target a more impactful cyber attack on your assets.

Scareware

Scareware is a malware tactic that insists users download or install a particular software which can help them avoid a “fake” danger or risk. It does that by tricking the user into downloading a useless antivirus software to clean an X number of infected files, prompted by a malicious program.

The motive of attackers behind targeting scareware is to extort money as a license fee of the software or to trick users into downloading a more lethal malware in their device and sometimes slide ransomware. Usually, it uses social engineering techniques to infect your devices and cause damage.

Ransomware

Ransomware is a type of malware that encrypts user data and information stored on a device and demands a ransom from the actual user to decrypt and unlock it. Sometimes, attackers can also use it as an instrument to threaten the user with a warning of exposing their data publicly.

File-encrypting ransomware adopts a cryptoviral extortion technique, where the private key is never shared with the victim.

Ransomware can have a tremendous impact on costs, and the reputation of an organization. It’s necessary to lay down appropriate precautionary measures and have an incident response plan if a situation ever turns up.

Trojan horses

Trojan horses are malicious programs that are disguised as the software you trust. It appears to be benign but has hidden malicious purposes. It delivers the attacker tools to the host by adding malicious files or replacing the existing files with the infected ones.

A trojan, masquerading as a legitimate file, impacts the host when a user executes it. In modern times, remote-access trojans (RAT) have become increasingly popular, allowing attackers to gain remote control over victims' devices. Attackers leverage RATs to move laterally and infect a network in an organization.

Trojans can pose challenges for your security defense as they can be tweaked and re-written to overcome your preventive security measures. Anti-malware programs try their best to combat trojans, but honestly, there are too many to keep up with as cybercriminals push out millions of variations of trojan horses every month.

Fileless malware

Fileless malware is a type of malicious software that uses legitimate programs to infect a device, without relying on files. It leaves no footprint, which makes it even harder to detect its presence in a system.

A fileless malware attack falls into a broader category of low-observable characteristic (LOC) attack. It’s a type of stealth attack, which poses a challenge in detection for many security solutions.

In the case of fileless malware, the malicious program goes straight into the memory, without being stored on the hard drive, and is, therefore, tricker to trace in forensic analysis.

Polymorphic malware

Polymorphic malware constantly changes its identifiable feature to avoid detection. The technique includes changing identifiable characteristics like encryption keys or file names, keeping the malware hidden from security solutions.

Even if the characteristics of the malware change its function still remains the same. Polymorphic malware can include types of viruses, worms, bots, keyloggers, or others.

To protect against polymorphic malware, here are a few tips that will come in handy:

  • Ensure your software is up to date with patches for known vulnerabilities.
  • Avoid clicking on suspicious links or email attachments.
  • Employ behavior-based detection tools like endpoint protection software and others.
  • Use strong passwords, and change them frequently.

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Malware on Android

All types of malware can risk your cybersecurity and enable cybercriminals to exploit your data and information stored on your devices. Anyone wouldn’t want the presence of malware on their devices, and to do that, first, you should know if to check if there is malware present.

How to check for malware on Android

To infiltrate an Android device, malware typically takes one of the two approaches: either it tricks you into granting access permissions to sensitive information or exploits a vulnerability on your Android device.

Either approach can put your mobile at risk. You won’t be sure as to what is actually happening to your device, but there will be signs to tell you that something is out of the ordinary.

Here are a few signs that suggest malware infections on your device:

  • Regardless of the app you use, ads would constantly populate on your screen.
  • The battery will drain out at a faster pace.
  • Unrecognized apps will get downloaded on your phone without your consent.
  • After installing an application, its icon would disappear immediately.
  • Data usage will skyrocket, even when you are barely using internet services.
  • Applications and services will crash more frequently.
  • Observable increase in the amount of heat radiated.

Once you’ve observed signs of malware infection, it’s advisable to check if the malware is actually present on your Android device.

You can do it by following a simple step-by-step process:

  1. Open the Google Play Store application on your device.
  2. Tap the icon on the top-left corner that stages three dashes arranged parallelly, and open the side panel.
  3. Once you’ve opened the side panel, go to Play Protect listed with a shield icon encompassing the logo of Play Store.
  4. When you go into Play Protect, click on the scan button.
  5. If your device has malicious applications, you’ll get an option to remove them here.
  6. This way, you can be sure if you’re dealing with malware on your mobile or it’s a completely different issue.

Best practices to prevent Android devices from malware

You can adopt certain practices to keep malware away from your Android devices. It’s advisable to follow these religiously because even minor carelessness can lead you to unprecedented outcomes of a malware attack.

Here are a few best practices:

 

  1. Always download applications from verified sources.
  2. Keep your applications and your Android OS updated to cover newly discovered vulnerabilities.
  3. Review the access permissions that you grant to specific applications.
  4. Follow a zero-trust policy when it comes to granting access permission and revoke if not required. For instance, if a game doesn’t need access to your contacts, consider revoking its permission at the earliest.
  5. Consider downloading antivirus software on your device. This software would have heightened access to your device to discover malicious behaviors and patterns, so only choose the antivirus software you can trust.

Following these practices will help you keep malware infections at bay. Still, if you feel that there is something terribly wrong with your Android device, waste no time and take it to a specialist who can identify the issue objectively.

Malware on Mac

It’s not as bizarre as you think. Even though Apple keeps and maintains a robust security perimeter across its devices and software, it still can be vulnerable to malware threats.

Apple’s built-in malware detection and file quarantine capabilities make it less likely that you’ll run a malicious program. But where security is the primary concern, you give your Mac the benefit of doubt.

If your Mac is acting strange or has been a lot sluggish lately, it’s likely that it could be due to a technical error, or a minute bug in the operating system. But this is also a sign of malware infection. In such situations, adding an extra layer of security with anti-malware programs specifically designed for Mac can be a wise decision.

To give a comprehensive idea of what does malware look like on Mac, here are a few recent examples:

1. GravityRAT: The infamous malware that targeted attacks against Indian military services previously, made its appearance on Mac (Kaspersky report). This malware takes advantage of stolen developer certificates to bypass Gatekeeper, where it attaches to legitimate programs developed with Python, .net, and Electron, and tricks users to download it.

2. XCSSET malware: It spreads through Xcode projects on Github and exploits vulnerabilities in Webkit and Data vault. They penetrate through the Safari browser to access login details for Google, Paypal, Apple, and Yandex services.

3. OSX/CrescentCore: It appeared in June 2019 on several websites, and also search engine results where it disguised itself as a DMG file of Adobe Flash Player. In an unsecure machine, it would install either a file called LaunchAgent. Crescent Core was able to bypass Gatekeeper as it had a signed developer certificate.

4. OSX/Linker: It emerged in May 2019, when it exploited a zero-day vulnerability in Gatekeeper to penetrate a MacOS.

5. Crossrider (OSX/Shlayer): It was a new variant of adware that infected Macs back in February 2018. It used a fake Adobe Flash Player installer to penetrate into the system, where the installer unloads a copy of Advanced Mac Cleaner which tells you in Siri’s voice that there were a few problems in your system.

Even when Apple strives consistently to guard against malware threats, it can still occur and put your system at risk. So if you think something strange is happening on your Mac, it’s advisable to check for signs of malware infection.

You can check for the following signs that can suggest a malware infection on Mac:

  1. Ads and pop-ups are populating your screen unexpectedly.
  2. The system is slow for no possible reason.
  3. The anti-malware software confirms an infection.

How to protect your Mac from malware

Malware can be troublesome, and when you are using a Mac, the first step in prevention is to realize that even after robust security protocols, malware can still enter your system. It’s advisable to have an extra layer of protection such as endpoint protection software installed so that if the infection occurs, you’ll have the technological arsenal set to combat it thoroughly.

You can adopt the following best practices to protect your beloved Mac from malware attacks.

Update your operating system and application

The updates patch newly discovered security vulnerabilities. Delaying on updating your software will make you prone to exploits, as the new vulnerability would be documented, and your system will still be at its risk.

When you install system updates, it updates X-Protect, Mac’s hidden anti-malware program, maintaining security against malicious programs.

Install the software you trust

One of the ways by which malware enters your system is by piggybacking on legitimate software. Installing software from pirated sites puts your Mac at unprecedented risks and it would be hard to tell what kind of infection you’ll let penetrate into your system.

By default, your Mac is set to install applications from the App Store or legitimate sources. It’s paramount that you don’t bypass this security layer to install an application that you don’t trust completely.

Disable Flash and Java plugins

Malware can enter your Mac by exploiting Java and Flash plugins on the web browser. By default, Safari disables them, but if you override and enable these plugins, make sure you added the most recent update, and are using it only in places where they are absolutely necessary.

It’s advisable to keep these plugins disabled, as they are one of the common attack vectors that converge a malware attack on Mac. While using the web on this day and time, these plugins are not needed anymore, and you can disable them without a risky second opinion.

Run malware scans

Even though MacOS has framed a robust security construct around its devices, it won’t hurt to run a few periodic malware scans, so that your treasured machine gains a benefit of extra security.

You can install the best endpoint protection software, which not only keeps your devices safe from malware but also provides multiple safeguarding tools like firewall, virtual private networking, and more.

Malware on Microsoft Windows

Signs of malware infections are mostly similar in MS Windows when compared to other operating systems. Majorly, your system will become slower, you’ll see a coup of ads putting hurdles in your normal work, or you can see warnings from unrecognized apps trying to extort a ransom and many others echoing the possibility of infection.

How to prevent malware on Windows

Hackers have been authoring malign programs to evade your digital information for days and ages now, and with time, their expertise has only improved. It’s your responsibility to keep your machine safe from evolving malware threats, and laying out the protective measures against it.

Like any other operating system, the security measures remain the same in its root. Still, we will give you the surefire ways in which you can protect your Windows machine from getting infected by a malware program.

The protective measures are as follows:

  • Use updated versions of software, and ensure that automatic updates are turned on.
  • Beware of phishing or other social engineering attacks targeted on your computer via email or other instant messaging applications. Use email anti-spam software to add-in an extra layer of security.
  • Block malicious websites and refrain from downloading any software from untrusted sources
  • Avoid downloading pirated content from any website.
  • Use an account without administrator permissions, unless it’s absolutely necessary.
  • Maintain a backup of your data stored on your system, both offline and on the cloud.
  • Create strong passwords for your applications, and try not to write them on places from where they can be stolen or accessed by others.
  • Avoid using untrusted devices to log on to your email, corporate or social accounts.
  • Use legitimate antivirus software to protect your PC from various kinds of threats.

It’s advisable to upgrade your operating system to Microsoft Windows 10, as it stages Windows Defender running actively to pin-point various malware threats or risks.

Keep the attackers at bay

Malware poses a threat to cybersecurity, which is too fatal to be overlooked. You need to keep a critical eye on the patterns that tell you about malware infection, or the signs that can trick you into being a victim of a malware attack.

Humans are quite possibly the weakest link that threat actors can use to penetrate into our devices, making it indispensable for us to update our knowledge as well as our tools to combat security threats.

Want to know more about techniques that hackers can use to penetrate into your assets? Start with the basic guide to ethical hacking today.

Sagar Joshi
SJ

Sagar Joshi

Sagar Joshi is a former content marketing specialist at G2 in India. He is an engineer with a keen interest in data analytics and cybersecurity. He writes about topics related to them. You can find him reading books, learning a new language, or playing pool in his free time.