Poisoning AI with ".аss" subtitles

Introduction

This tutorial explores the concept of manipulating subtitle files in the .ass format to illustrate vulnerabilities in AI systems. We will focus on creating a "poisoned track" that can disrupt automated processes, particularly in video playback. This guide is relevant for those interested in understanding subtitle formats, data handling, and the potential implications of poorly managed AI systems.

Step 1: Understanding the .ass Subtitle Format

• The .ass (Advanced SubStation Alpha) format is a text-based subtitle file that supports advanced styling.
• It allows for detailed control over the appearance of subtitles, including font, size, and positioning.
• Familiarize yourself with the structure of .ass files, which typically include sections for styles, events, and metadata.

Key Components of .ass Files

• [Script Info]: Metadata about the subtitle file.
• [Styles]: Definitions for how subtitles will look.
• [Events]: The actual subtitle text and timing.

Step 2: Creating a Poisoned Subtitle Track

• Open a text editor and create a new file with the .ass extension.
• Start by defining the script info section:

[Script Info]
Title: Poisoned Track
Original Script: Your Name
ScriptType: v4.00
Collisions: Normal
PlayDepth: 0

• Next, define styles that may be overly complex or heavy:

[Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, TertiaryColour, BackColour, Bold, Italic, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, AlphaLevel, AlphaLevelUD, Clip, ScaleX, ScaleY, Spacing, Angle, BorderColour, OutlineColour, ShadowColour
Style: HeavyStyle, Arial, 60, &H00FFFFFF, &H000000FF, &H00000000, &H00000000, 1, 1, 1, 5, 0, 2, 10, 10, 10, 0, 0, 0, 1, 1, 0, &H00000000, &H00000000, &H00000000

• Create a series of events that use this heavy style:

[Events]
Format: Marked, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: Marked=0, 0:00:01.00, 0:00:05.00, HeavyStyle, , 0, 0, 0, , This is a test of a poisoned subtitle track.

Step 3: Testing Your Subtitle Track

• Load your .ass file into a video player that supports advanced subtitles (like VLC or MPC-HC).
• Observe how it affects performance and playback. In some cases, heavy styling can cause crashes or lag.

Practical Tips

• Use a normal styled subtitle track for comparison to understand the impact of the "poisoned" track.
• Always back up original subtitle files before testing.

Conclusion

In this tutorial, you learned how to manipulate .ass subtitle files to create a "poisoned track" that can disrupt AI processing. This exercise serves as a reminder of the importance of proper data management and the potential vulnerabilities that can arise from complex data formats. As a next step, consider exploring additional vulnerabilities in AI systems or experimenting with different subtitle effects to further understand their impact on media playback.