Autopsy User Documentation  4.5.0
Graphical digital forensics platform for The Sleuth Kit and other tools.
Image Gallery Module

Overview

This document outlines the use of the new Image Gallery feature of Autopsy. This feature was funded by DHS S&T to help provide free and open source digital forensics tools to law enforcement.

The new image gallery feature has been designed specifically with child-exploitation cases in mind, but can be used for a variety of other investigation types that involve images and videos. It offers the following features beyond the traditional long list of thumbnails that Autopsy and other tools currently provide.

This document assumes basic familiarity with Autopsy.

Quick Start

  1. The Image Gallery tool can be configured to collect data about images/videos as ingest runs or all at once after ingest. To change this setting go to "Tools", "Options", "Image /Video Gallery". This setting is saved per case, but cannot be changed during ingest. See the Options window for more details
  2. Create a case as normal and add a disk image (or folder of files) as a data source. Ensure that you have the hash lookup module enabled with NSRL and known bad hashsets, the EXIF module enabled, and the File Type module enabled.
  3. Click the "View Images/Videos" button or select "View Images/Videos" in the "Tools" menu. This will open the Autopsy Image/Video Analysis tool in a new window.
  4. Groups of images will be presented as they are analyzed by the background ingest modules. You can later resort and regroup, but it is required to keep it grouped by folder while ingest is still ongoing.
  5. As each group is reviewed, the next highest priority group is presented, according to a sorting criteria (the default is the density of hash set hits).
  6. Images that were hits from hashsets, will have a dashed border around them.
  7. You can use the menu bar on the top of the group to categorize the entire group.
  8. You can right click on an image to categorize or tag the individual image.
  9. Tag files with customizable tags. A ‘Follow Up’ tag is already built into the tool and integrated into the filter options. Tags can be applied in addition to categorization. An image can only have one categorization, but can have many tags to support your work-flow.
  10. Create a report containing the details of every tagged and/or categorized file, via the standard Autopsy report generation feature.

Use Case Details

In addition to the basic ideas presented in the previous section, here are some hints on use cases that were designed into the tool.

Categories

The tool has been designed specifically with child-exploitation cases in mind and has a notion of categorizes. We will be changing this in the future to be more flexible with custom category names, but currently it is hard coded to use the names that Project Vic (and other international groups) use. We have assigned colors to each category to highlight each image.

NameDescriptionColor
CAT-0Uncategorized
gray.PNG
gray
CAT-1Child Abuse Material
red.PNG
red
CAT-2Child Exploitative / Age Difficult
orange.PNG
orange
CAT-3CGI / Animation
yellow.PNG
yellow
CAT-4Comparison Images
bisque.PNG
bisque
CAT-5Non-pertinent
green.PNG
green

GUI controls

You can do your entire investigation using the mouse, but many examiners like to use keyboard shortcuts to quickly process large amounts of images.

Keyboard Shortcuts

shortcut action
digits 0-5 assign the correspondingly numbered category to the selected file(s)
alt + 0-5 assign the correspondingly numbered category to all files in the focused group
arrows select the next file in the direction pressed
page up/down scroll the list of files

Additional Mouse Controls

mouse gestureaction
ctrl + left clicktoggle selection of clicked file, select multiple files
right click on filebring up context menu allowing per file actions (tag, categorize, extract to local file, view in external viewer, view in Autopsy content viewer, add file to HashDB)
right click empty space of groupbring up context menu allowing per group actions (tag, categorize, extract to local file(s), add file(s) to HashDB)
double click on fileopen selected file in slide show mode

UI Details

Group Display Area

The central display area contains the list of files in the current group. Images in the group can be displayed in either thumbnail mode or slide show mode. Slide show mode provides larger images and playback of video files. At the right of the group header is a toggle for changing the viewing mode of the group (tiles vs slide-show ).

Image/Video Tiles

Each file is represented in the main display area via a small tile. The tile shows:

image description meaning
solid colored border file’s assigned category.
purpledash.PNG
purple dashed border file has a known bad hashset hit, but has not yet been categorized.
hashset_hits.PNG
pushpin file has a known bad hashset hit
video-file.PNG
clapboard on document video file
flag_red.PNG
a red flag file has been 'flagged' as with the follow up tag

Slide Show Mode

In slide show mode a group shows only one file at a time at an increased size. Per file tag/category controls above the top right corner of the image, and large left and right buttons allow cycling through the files in the group. If the active file is an Autopsy supported video format, video playback controls appear below the video.

Table/Tree of contents

The section in the top left with tabs labelled “Contents” and “Hash Hits” provides an overview of the groups of files in the case. It changes to reflect the current Group By setting: for hierarchical groupings (path) it shows a tree of folders (folders containing images/videos (groups) are marked with a distinctive icon ), and for other groupings it shows only a flat list.

Each group shows the number of files that hit against configured Hash DBs during ingest (hash hits) and the total number of image/video files as a ratio (hash hits / total) after its name. By selecting groups in the tree/list you can navigate directly to them in the main display area. If the Hash Hits tab is selected only groups containing files that have hash hits are shown.


Copyright © 2012-2016 Basis Technology. Generated on Fri Dec 15 2017
This work is licensed under a Creative Commons Attribution-Share Alike 3.0 United States License.