There are many types of files that we can receive and that are actually a threat to our security. As we know, when browsing the Internet we face many types of attacks that can put systems at risk. Luckily we can also make use of many tools and techniques that can protect us. However in general we can say that common sense is the most important. In this article we are going to focus on explaining how to know if a PDF or image we receive may be malicious.
The danger of received files
Keep in mind that PDFs or images are not the only types of files that can be dangerous. However, we can say that they are files widely used by hackers to carry out their attacks. They are files that may go unnoticed, that may seem harmless, but can actually be a major problem.
Simply by sending a malicious file through email our computer can become infected. Hence what we mentioned before common sense. It is essential to always be alert and avoid that a simple image or PDF file that we have received could put our equipment in trouble.
Hackers typically hide malicious code in the files they mail. Simply opening or downloading them can execute that code and put our security at risk.
How to tell if a PDF or image is malicious
It is always important to protect our equipment and for this it is essential to know if the files that we receive or that we are going to install may be dangerous. If you have a document that contains malware, it could compromise the proper functioning of the system and also affect other computers that we have connected to that network. Hence, we must detect a hypothetical security threat as soon as possible.
See who sends it
One of the first things to consider when we receive a PDF or image by email is to see who is sending it. It is undoubtedly one of the main keys to detect possible malicious files that may affect us. Of course, it must be borne in mind that it is not something that shows 100% that it will be safe.
Do we know the address of the sender? Is it an address that looks suspicious? There we have some clues as to what that email may contain. We can also do a Google search to find information for that specific email. Surely some user has shown information in case it is some type of confirmed scam.
Without a doubt the subject of the message is also very important. Hackers will typically use message subjects to prompt you to open them. For example, they can use messages where they tell us that we have won a prize, that we have received something in a raffle or that our account has suffered a problem and we have to open it to have more information.
They can use these baits to later make the victim open that PDF or image. If we see this type of message we can verify that it may indeed be a scam and that, ultimately, these files are dangerous. We should never download them, unless we do it in a safe place and that it cannot affect our device.
Analyze the message
Also an important test is the message itself. A text may appear that clearly shows that it is a scam. It can be a bad translation, messages that warn that we must carry out an action that normally boils down to having to open that file to obtain more information, etc.
Therefore, the body of the message can also help us to detect if a PDF file or image that is attached can be a threat to our security. A simple glance may be enough to realize that it really is an attempt at deception, that it could be a Phishing attack or similar. There are many threats of this type that can reach our email and it is convenient to be aware of it.
On the other hand, the name of the file is also something that we must analyze. It is another clue that can tell us if it really is something legitimate or is it a file that has been sneaked there to infect our systems. It is important to analyze it.
Use analytics services
Sometimes those attachments have a link. We have to enter a link to download them. They can also use it to prevent the email provider from detecting it as a threat.
Luckily we have services that allow us to analyze those links. We simply have to copy the link and these types of tools tell us if there is any kind of problem and, ultimately, it may represent a threat to our security. We leave you an article where we show an online tool to analyze URLs .
In short, with these tips we can know if a PDF or image that we have received can be a threat. However, we can apply this to any type of file. But we also want to give some recommendations to be protected and that a hypothetical attachment does not affect our security:
- Use antivirus : security programs are very important to avoid problems. A good antivirus, for example, could detect if an attachment is a threat and thus be able to correct it as soon as possible. It is something that we must apply regardless of the OS we use.
- Have the system updated : of course it is very important to have our equipment with the latest versions. There are many occasions when security flaws can appear that could be exploited by hackers and compromise our privacy. We must always update everything we have.
- Avoid unofficial programs : Sometimes we can use third-party software to open email. They can have interesting functions that come in handy for our day to day. However, it could sometimes be dangerous and serve to attract spam, collect personal data, etc.
Therefore, by following these tips we can also avoid security problems with possible attachments. We must at all times maintain the reliability of the equipment and not make mistakes.