Safety of opening .txt files

Question

If I'm given a URL that points to a .txt file, is it always safe to open it? Can it possibly contain virus or malicious content?

Are you asking as a user? If you are then you're on the wrong forum. If you're asking as a programmer, then I'm no expert on operating systems, but I think it's _your_ responsability to read from the file safely. — Zecc, Oct 19 '12 at 21:19
This isn't really related to programming, so you might want to ask this on [Security.SE](http://security.stackexchange.com/) :) — Miguel, Oct 19 '12 at 21:20

score 5 · Accepted Answer · answered Oct 19 '12 at 21:28

5

A genuine txt-file can contain virus code but it cannot be executed, so it's totally safe. However, a file can use double file extension like this, so watch out:

a-virus-file.txt.exe

Windows hides by default .exe because it's a known file type.

answered Oct 19 '12 at 21:28

6

If it is a URL, why would the extension be hidden? – Austin Henley Oct 19 '12 at 21:38

score 3 · Answer 2 · answered Oct 19 '12 at 21:20

3

It is not safe to rely solely on a file extension. The real file type can easily be masked by someone changing the extension, so the file could easily be a virus or malicious content.

For example:

MyVirus.exe -> SeeminglyHarmlessFile.txt

answered Oct 19 '12 at 21:20

Seth

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This answer is rather.. confusing. You should specify, given there are two questions in the OP, not one. – Daedalus Oct 19 '12 at 21:21
@Daedalus The one question answers the other - since it could contain a virus, it is not always safe to open it. – Seth Oct 19 '12 at 21:22
Not what I meant; the first question is, 'is it safe to open x', you reply 'absolutely' without specifying which you are replying to. – Daedalus Oct 19 '12 at 21:23

Safety of opening .txt files

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