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 thing. In this article we are going to focus on explaining how to know if a PDF or image that we receive can be malicious .
The danger of received files
Keep in mind that PDFs or images are far from the only types of files that can be dangerous. However, we can say that they are files that are widely used by hackers to carry out their attacks. They are files that can go unnoticed, which 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 files they send in the mail. Simply by opening or downloading them, this code can be executed and put our security at risk.
How to tell if a PDF or image is malicious
See who sends it
One of the first issues to keep in mind when we receive a PDF or image file by email is to see who sends it . It is undoubtedly one of the main keys to detect possible malicious files that may affect us. Of course, keep 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? Here are some clues as to what that email may contain.
Message Subject
Without a doubt the subject of the message is also very important. Typically hackers will use message subjects that prompt them to open them. For example, they can use messages that tell us that we have won a prize, that something has touched us in a draw or that our account has suffered a problem and we must open it for 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 can indeed be a scam and that, ultimately, these files are dangerous.
Analyze the message
Also an important test is the message itself . A text may appear that is clearly a scam. It can be a bad translation, messages that alert us that we must carry out an action that is usually summarized in having to open that file to obtain more information, etc.
Therefore, the body of the message can also help us detect if an attached PDF or image file may be a threat to our security.
file name
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 if it is a file that has leaked 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 this type of tool tells us if there is any type of problem and, ultimately, it can pose 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.