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Why we should pay more attention to our Download folder

How many files have you got resting in your computer’s download folder? It’s normal that it gets filled with installation apps form all the different programs that we download from the Internet and then forget to delete. Although this seems harmless at first, what is certain is that it could lead to some serious problems for your computer.

A recently detected vulnerability in the Java installation program, a platform that many applications and websites need to function correctly, has put this seemingly innocuous area at risk.

The Java software needs to update itself periodically with new versions so as to be able to maintain the performance and security of the tools that it helps to run.

Its distributor, Oracle, has warned of a security issue that affects the installation programs of the platform’s 6, 7, and 8 versions. The company has therefore advised its users to delete these programs from the download folder and replace them with new ones if necessary.

The reason given is that the installation software is designed to automatically search and load a set of files that are included in the installation pack (including its own .exe file) and to the  store them in the same folder.

This procedure, which all installation programs carries out, shouldn’t pose a risk to your computer, as the majority of folders where they are stored aren’t vulnerable to attack. However, the “Downloads” directory is able to be modified.

If a cybercriminal manages to add this type of file (named Dynamic Link Library, or DLL), charged with malware, to the folder, the installation program will run it when the user wants to install Java for the first time, or if they manually update the tool by downloading a new installation program.

An added risk is that many browsers are set up to automatically download certain files, even if they don’t run later. Via an infected website, the attacker could use this feature to hide malware in the download folder without the user knowing about it. The files with malicious software would then be read to be executed by the installation program.

Deleting your browsing history would only help to eliminate the websites that you’ve visited, but not the programs that are already stored. Therefore, it is recommended that you delete the documents and software from your download folder every so often.

“Though considered relatively complex to exploit, this vulnerability may result, if successfully exploited, in a complete compromise of the unsuspecting user’s system”, says Eric Maurice, Head of IT Security at Oracle.