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My laptop got infected with a virus. It was "cleaned" by a professional but I am now reluctant to transfer files I had on my laptop to other computers.

I have plenty of images, MP4s, Word, PowerPoint and PDF documents that I would rather not nuke from orbit. Those are the only files that I would like to save (nothing executable and no programs).

Can I safely view these types of files on a Google Drive (without downloading them) from an uninfected laptop or is it best to use a Chromebook?

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  • yes it is safe. – yeah_well Dec 31 '20 at 17:08
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If the malware on your computer injected malicious macros (or some Microsoft Office exploit) into your documents, in an attempt to re-infect you or others when they are opened, then re-opening them in Office on your computer is potentially risky. The same goes for PDFs.

Google Drive's web-based preview of the documents does not cause the documents themselves to be downloaded to your computer - it instead interprets the content of the documents on the server side, and builds an interactive representation of the document content for you to view online.

The operating system you use to do this is irrelevant - you can use Windows, Linux, macOS, BSD, Android, ChromeOS, iOS, or whatever you like. You're not opening the actual documents locally.

I wouldn't worry too much about the images and videos. The likelihood of them containing a media player exploit is very small. The images I would just continue to use without any additional precautions. For the videos, just make sure you've got an up-to-date copy of VLC or MPC-HC.

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  • When we open Office Documents, PDF, image or video on Google Drive, is opened file temporarily saved on computer/phone cache to view? – user215422 Jan 1 at 10:04
  • So then from what I read here, it would be safe to strictly view any potentially infected PDFs, PowerPoints and word documents through the Google drive UI? – rogger k9 Jan 1 at 22:28
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    @user215422 No. The document is on Google's servers and only a web-rendered view of it is shown to you. – Polynomial Jan 1 at 23:36
  • @roggerk9 I wouldn't say it's secure in absolute terms, but it's certainly extremely unlikely to infect you unless you accidentally download and open the file. – Polynomial Jan 1 at 23:36
  • @Polynomial Thanks. If I understand right, "web rendered view of a file/image/video" means "file views stay in RAM, no data on disk". Right? – user215422 Jan 2 at 1:07
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Let's unpack this:

"... Can I safely view these types of files on a google drive (without downloading them)..."

When you view or edit a remote file, you are downloading it. You can see it only because it's on your computer. Depending on circumstances it may only be in memory, it may be written to a temp file, it may be in chunks if the file is exceptionally large, but it's on your computer.

"... images, mp4s, word, PowerPoints and pdf documents ... nothing executable and no programs ..."

Images like JPGs or videos like MP4s are not going to carry executable malware outside of torturous logic involving steg and third party executable malware. There have been some extremely rare exploits against graphic driver flaws in the past but the odds of encountering that are just about zero.

However there are a number of file types that are executable that might not seem like it and can carry malware . The old Windows ".wmf" graphic file contains an executable capability. So too might all Windows Office files like PowerPoint. Adobe PDF, while really convenient, has a very long history of many and continuing security issues with dangerous executable capabilities, that's why there's concerted effort industry wide to stop using PDF.

"...Can I safely view these types of files ... from an uninfected laptop or is best to use a Chromebook?"

I'm guessing you are referring to using a different operating system than Windows, under the assumption of Windows only malware? Using a different operating system will help provide a buffer, but cross platform malware is not unusual in scriptable mechanisms such as MS Office and PDF's.

How likely is it that you may encounter these types of malware I can't say. The safest way to handle it is to use a non-persistent OS that can't be infected past a power cycle. (Yes there are extremes of BIOS/GraphicCard/etc modifications but it's not a significant concern.)

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    This isn't all strictly true - if you're viewing a Powerpoint or Excel document on Google Drive or Google Docs, you're not downloading the PPTX or XLSX files themselves to your computer, and your installed copy of Office is never touching them. Google parses the documents for you on the server-side and presents you with an interactive web-based visualisation of their content. This means that if there are any malicious macros in the documents, they're not able to harm your computer. – Polynomial Dec 31 '20 at 18:49
  • @ Polynomial - Yes, if you're using a remote engine to process the file you may only be getting the video portion. VNC and other remote terminals operate this way. – user10216038 Dec 31 '20 at 21:15

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