How To Scan Zip Files For Viruses And Zip Bombs?

A Zip File is a binary file format that creates a single file for multiple files for easy access as well as facilitates to sharing of large as well as multiple files over the internet. It provides user convenience in that it enables people to transfer, store, and share relatively small files. However, this convenience comes with a risk: Just like regular folders, zip files contain files and folders and might contain viruses, or a specific type of virus called zip bomb.

These threats are detrimental to the security of your computer since they can erase your data, freeze the operating system, or grant third parties access to information they are not supposed to see.

Here in our article, let’s follow through on how one can properly scan zip files for all these threats and how to ensure your computer’s safety. The preceding sections outlined the steps of using a good antivirus program, other stand-alone anti-virus programs, and online virus scanning services, in this part, there are other useful tips to avoid zip bombs.

• Zip Files: These are storage formats, which compress several files into one single shipment package. This makes files smaller in size and therefore improves the ease of managing and transferring files.

• Viruses: Meaningful software is the one to damage the computers or steal the users’ information. This type of virus can be encased in the files that are located inside an archive. zip folder.

• Zip Bombs: Also known as decompression bombs, these are maliciously crafted zip files designed to crash or freeze your computer by causing an extreme load on your system resources when decompressed.

1. Always install genuine Antivirus Software

• Step 1: Make sure your antivirus is updated. It means that an updated antivirus program will be equipped with the newest virus definitions to scan for new threats.
• Step 2: Remember to set your antivirus to scan compressed files. It is to be noted that the majority of contemporary anti-virus applications have options for scanning files that are archived within zip files.

• Step 3: Extract the zip file to a directory in your local system, but do not proceed to the next step.

• Step 4: Go to the downloaded zip file and right click on it and then select to scan with antivirus.

Example Antivirus Programs

• Norton Antivirus
• Kaspersky
• Bitdefender
• McAfee

2. Use Dedicated Malware Scanner

Comprehensive anti-malware tools can be installed to provide another layer of security because of their specialty which is to scan for malware and even within archived files.

Examples of Malware Scanners

• Malwarebytes
• Spybot Search & Destroy
• AdwCleaner

3. Utilize Online Virus Scanning Services

Remote virus scanning services are those where the files and documents can be scanned without downloading the program into the computer system.

Popular Online Scanners:

• VirusTotal: This enables you to upload files (even consolidated zip files) in that it scans with multiple AV engines.

• Metadefender: Like Virus Total, it is an application that uses several engines to search for threats within the computer system.

Steps:

1. In case one has a convenient option, browse through the website of the online scanning service.
2. Upload the zip file.
3. Check the output of the test and wait for the scanning process to be finished.

4. Be Cautious with Unexpected or Unknown Sources

Zip files from unknown or unexpected sources should always be treated with caution. If you receive a zip file from an untrusted source or unsolicited email, it’s best to verify its legitimacy before downloading and scanning.

• Use Software That Limits Resource Usage: Some antivirus software has other mechanisms for protecting computers from zip bombs by restricting either the amount of memory or time taken in uncompressing archives.

• Employ File Size Limits: To prevent the downloading of files that fill your hard disk space, set your antivirus or operating system configurations to delete files with very large sizes upon download or zipped files that are very big when unzipped.

• Stay Informed: It is important to introduce new threats that are likely to happen now and new security measures that should be taken.

Yes, modern antivirus software is indeed capable of scanning zip files for virus presence. These programs can extract the contents of compressed files without necessarily unzipping the files as it is done normally. This capability is necessary to detect and mitigate threats that can be inside the Zip archives. When picking an antivirus, check if it is capable of scanning compressed files as this is a very important feature.

A zip bomb or decompression bomb is therefore a file that is designed to kill a computer by overloading the resources it has. A zip bomb, when extracted, takes up a large amount of memory as well as time, which is why it is called a bomb. This can result in system sluggishness, crashes, or total failure of the entire system. The purpose of the zip bomb is to harm the system and, in the best-case scenario, make it useless. Currently, most antivirus programs have features that enable them to detect and block zip bombs when they are unzipped so as not to affect the system.

• Use Software That Limits Resource Usage: Thus, some antivirus programs already define measures that can be used to shield against zip bombs by restricting the number of CPU time or memory that can be used in the unzipping of archives.

• Employ File Size Limits: Configure your antivirus or operating system to reject overly large zip files or files that expand to an excessively large size when decompressed.

• Stay Informed: Keep yourself updated about the latest types of threats and recommended security practices.

Another measure that is also worthwhile touching upon is the activity of scanning the zip files for viruses and zip bombs regularly. There are four steps that one can help minimize the risk of getting contaminated and save your device they are, first, install reputable antivirus software, second, scan with reliable anti-malware, third, use online scanning services and fourth, avoid unknown suspicious websites. However, it should be understood that protection is not simply the act of using the software or knowing that such tools exist, but rather, that appropriate tools are used and one knows about their existence.

What should I do when I receive a zip file and the antivirus software declines it to be a virus?

If currently the virus is being detected, they should not open the zip folder. As per the instructions of the antivirus software, normally the software points towards deletion or quarantining of the file in question.

Are the online virus scanners fit for use?

Yes, there is nothing wrong with using online virus scanners such as VirusTotal and Metadefender which are genuine applications that can use multiple virus scanning engines in order to scan infected files.

What warning signs should I be cautious of in order not to fall victim to a zip bomb?

Usually, zip bombs are programs or files, often taking little disk space, which in reality contain massive data or numerous copies of itself. Another question is related to their origin – they can be received from untrusted or suspicious sources, so their efficiency is questionable.

Can I scan the content of the compressed files placed in zip files without unzipping them?

Yes, nowadays nearly every antivirus program is capable of scanning the zip files without decompressing them, as they look for the viruses within the archive.