IT Security Stack Exchange
IT Security Stack Exchange

Questions tagged [file-types]

51 questions
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Is there a need to scan images with real-time scanners anymore?

Historically, there were some exploits for certain types of image files, notably JPEG images. Consequently, many real-time malware scanners (antivirus included) started scanning every JPEG image (as well as some other types of image files) every…
RockPaperLz- Mask it or Casket
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Why are PDFs less secure than other document formats?

My email client will flag up PDFs as potentially insecure, but won't do the same for other document formats such as PPTs. Why is this?
fredley
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Do you know any .xry reader for MacOS/*BSD or Linux?

I am looking for a .xry reader (software) that works on mac/*bsd/linux in order to perform a forensic analysis. Can you suggest one?
gbr
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Ensuring that non-executable files are not malicious

Let's say that I have been sent some maliciously-crafted audio files by an attacker that use an unpatched security exploit somewhere in my system to compromise it. How can I reprocess the actual audio (or image, or text etc.) content of such a…
user8490210
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Can .ai files (Adobe Illustrator) be malicious?

They are blocked by our email gateway, but are also needed for some workflows. Can these files even contain malicious content and possibly execute code?
Mia
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Changing file extensions in PHP file upload to prevent code execution?

I think in a PHP file upload it is a best practice to store files outside of the document root with a randomly generated file name and telling the server to make them non-executable, so the file will not be executed by an attempt to access the file…
kot
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Is there a ransomware variant that checks for file's magic numbers to encrypt?

Is there a known ransomware-variant (Cryptolocker, Cryptowall etc.) that before encrypting the files checks for their magic numbers? Lets say that there's a Word file, that had its file extension removed or changed to a not-popular one. We'll call…
Laen
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My MP3 file is blocked, but still playable?

My computer is telling me that my MP3 file is blocked: I have no problems playing the song, so I was wondering what exactly does it mean for my MP3 file to be blocked?
Pacerier
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Why is VirusTotal "unable to process file type" for files packed with Mpress?

Packed an AutoHotkey script with ahk2exe using MPress, got 13 hits on the VirusTotal online scan for the zipped result. Packed the same script with the same ahk2exe without MPress and got just 6 hits on the zipped result. Zip performed with…
Laurie Stearn
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What kind of encryption is this file using? It used to be plain text

I was collecting data and building a database from a mobile game on Android. Here's an after/before image. If I do CTRL + A and copy paste on the left side, all information gets copied to clipboard is this: DB‘AÛÀÜtÿ$Lº‡VI¦ However I can select…
Tuğberk Kaan Duman
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What is an electronic document in the context of encryption?

I'm reading about a Public key certificate: In cryptography, a public key certificate, also known as a digital certificate or identity certificate, is an electronic document used to prove the ownership of a public key. From the wiki for an…
mbigras
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Can you trace someone through picture header information?

I learned that jpg, png, bmp and most image files contain headers and plain text in them. I decided to open a jpg file in Notepad and saw a bunch of information and I was wondering if there was a way to find out the origin of the computer it came…
Edward Severinsen
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Forensic analysis of file metadata

Suppose I have received a file (doesn't matter what it is - document, image, video, audio, etc). I know that the operating system and also programs that create the file like Office, and even hardware like digital cameras, etc. store a lot of…
ose
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Beside GIFAR are there any other known polyglot files?

A GIFAR file is a polyglot file with a fancy name. It can be "opened" both as a valid GIF file and a valid JAR file thus leading to security issues under certain circumstances. Definition of a GIFAR file : Graphics Interchange Format Java Archives…
ForguesR
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Thousands of files (png, pdf, tex, java, cpp, etc.) deleted on Mac OS X Yosemite

Yesterday, I noticed that, starting at 12:40, many thousands files had been automatically deleted from my drive. The computer is a Macbook Pro with a recent version of Mac OS X Yosemite. Since many folders are under Git version control, I could run…
Pimin Konstantin Kefaloukos
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