Detect viruses and Trojans

In the current technological era, coming across different computer problems related to malware and cyber attacks is common.

According to AV-TEST Institute, there are more than 1 billion malware programs available and new malware programs are detected regularly. Hi guys and welcome to yet another interesting post by Blueguard. But before we begin, if you love reading our tech posts like this one, subscribe to our website by hitting the follow button, so that you will never miss an update. In this post, 

  • We'll understand what is a malware program.
  •  Then we'll see what exactly are viruses and trojans. 
  • Then we'll see how they operate in our system.
  • And then different types of viruses and trojans.
  • And how to detect the activity of such programs.
  • And we'll see how to prevent our system from getting infected by such programs. 
  • Lastly we will see the basic difference between virus and Trojans 

What is Malware?

Malware is a malicious software that is programmed to cause damage to a computer system, network and hardware devices. Many malicious programs like trojans, viruses, worms and bots which cause damage to the system are known as malware. Most of the malware programs are designed to steal information from the targeted user or to steal money from the target by stealing sensitive data. 

Let's take a look at the introduction for two different types of malware, virus and trojans.


Firstly, let's take a look what exactly is a virus program. A computer virus is a type of malicious program that on execution replicates itself. They get attached to different files and programs which are termed as host programs by inserting their code. If the attachment succeeds, the targeted program is termed as infected with a computer virus. 

Trojan horse 

Trojan horse program is a program that disguises itself as a legitimate program but harms the system on installation. They hide within the attachments and emails then transfer from one system to another. They create bad doors into our system to allow the cybercriminal to steal our information. 

How Different Malware Works 

Let's take a look how they function after getting installed into our system.

How Computer Virus Works 

Firstly, we have virus programs. The computer virus must contain two parts to infect the system. First is the search routine which locates new files and data that is to be infected by the virus program.

And the second part is known as the copy routine which is necessary for the program to copy itself into the targeted file which is located by the search routine. 

How Trojans Works

For trojan horses, entry way into our system is through emails that may look legitimate but may have unknown attachments. And when such files are downloaded into the device, the trojan program gets installed and infects the system. They also infect the system on the execution of infected application or the executable file and attacks the system. 

Types of Viruses and Trojans 

Now that we understand what virus and trojans are, let's understand different types of virus and trojans. 

Types of Viruses 

  1. The first one is known as the boot sector virus. This type of virus damages the booting section of the system by infecting the master bot record which is also known as MBR. This damages the boot sector section by targeting the hard disk of the system. 
  2. Then we have the macro virus. Macro virus is a type of virus that gets embedded into the document related data and is executed when the file is opened. They also are designed to replicate themselves and infect the system on a larger scale. 
  3. And lastly, we have the direct action virus. This type of virus gets attached to executable files which on execution activates the virus program and infects the system. Once the infection of the file is completed, they exit the system which is also the reason it is known as a non-resident virus. 

Types of Trojan Horse 

  1. The first type of trojan is the backdoor trojan. They are designed to create a backdoor in the system on execution of an infected program. They provide remote access of a system to the hacker. This way, the cybercriminal can steal our system data and may use it for illegal activities.
  2. Next we have Cryxos trojan. They enter the system by clicking the random pop-ups which we come across on the internet. They attempt the user to give their personal details for different transactions or schemes, which may provide remote access of a system to the cybercriminal. 
  3. And the last Trojan type is Ransom Trojan. This type of Trojan program after entering the system blocks the user from accessing its own system and also affects the system function. The cybercriminal demands a ransom from the targeted user for the removal of the Trojan program from the device. 

Now that we understand some details regarding viruses and Trojan let's solve a question. The question is Shema was denied access to her system and he wasn't able to control the data and information in her system. 

Now the actual question is what could be the reason behind her systems problem? 

  • Option A, macro virus. 
  • Option B, ransom Trojan. 
  • Option C, backdoor Trojan. 
  • Option D, boot sector virus 

Give your answers in the comment section. 

How to Detect Activity of Viruses and Trojans in Your System?

Let's understand how to detect the activity of viruses and Trojan in a system. To detect virus or Trojan activity in a system we can refer to the following points. 

How to Detect viruses?

For viruses we have slowing down of the system and frequent application freeze shows that the infection of the virus is present in the system.

Then, viruses can also steal sensitive data including passwords, account details which may lead to unexpected logout from the accounts or corruption of the sensitive data.

And lastly we have frequent system crashes due to virus infection which damages the operating system. 

How to Detect Trojans?

For Trojan we have frequent system crashes and system also faces slow reaction time. 

Then we have more random pop-ups from the system which may indicate Trojan activity.

And lastly we have modification in the system application and change of the desktop appearance can be also due to the infection of a Trojan program. 

Famous Cyber Attacks for Virus and Trojans 

Next let's take a look at a famous cyber attack for virus and a Trojan horse. 

For virus we have the mydome virus which was identified in the ER 2004 which affected over 50 million systems by creating a network of sending spam emails which was to gain backdoor access into our systems. 

Next for the Trojan horse we have the Emotat Trojan program which is specifically designed for financial theft and for stealing bank related information. 

How to Prevent Entery of Virus and Trojans into our System 

Next we have few points for how to prevent virus entry or Trojan attack for our system. 

The most basic way of virus protection is to using antivirus and do regular viruses scan. This will prevent virus entry in the system and also having more than one antivirus provides much better protection. 

Then avoid visiting uncertified websites can also prevent virus entry into our system. 

Then we have using regular driver updates and system updates to prevent virus entry. 

For Trojan we have using certified softwares from legal sites to prevent any Trojan activity in our system and also avoid clicking random pop-ups that we often see on the internet and lastly using antivirus and good habit. 

Difference Between Virus and Trojan Horse 

For the first part we saw the main objective of the virus is to harm the data and information in a system whereas for the Trojan we have stealing of the data files and information. Effect of viruses is more drastic in comparison to the Trojan horses. Then we have viruses which are non-remote programs whereas Trojan horses are remote accessed and lastly viruses have the ability to replicate itself to harm multiple files whereas Trojan does not have the replication ability. 


Now that we have reached the end of the post please just take a look what you have learnt. If you have any questions you can ask on the comment section. Thank you for reading and if you like this post subscribe to the Blueguard blog and share it to friends and family.

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