File Download and Browser Activity Investigation Guide

asComplete DFIR Workflow & Cheatsheet


πŸ“š Table of Contents


🎯 Investigation Framework

Artifact Priority Matrix

Investigation Goal
Primary Artifacts
Secondary Artifacts
Timeframe

Malware Download

Browser Downloads

Browser History, WebCache

15-30 min

Phishing Investigation

Browser History

Downloads, Email Attachments

20-40 min

Data Exfiltration

Browser History (uploads)

Downloads, Email

30-60 min

Suspicious File Access

WebCache file:///

Browser History

15-30 min

Drive-by Download

Browser History + Downloads

Cache files

30-45 min

Email-based Compromise

Email Attachments (OST/PST)

Browser Downloads

45-90 min

User Web Activity

Browser History (all)

Downloads, Cache

30-60 min

Timeline Construction

All browser artifacts

File system timestamps

60-120 min


πŸ” Quick Triage (First 15 Minutes)

Determine Investigation Scope

Quick Win Queries

Check for Recently Downloaded Executables:


🌐 Browser History Analysis

Overview

Purpose: Reconstruct web browsing activity, identify malicious sites, track user behaviour

Key Information Available:

  • URLs visited

  • Visit timestamps

  • Visit frequency (number of visits)

  • Page titles

  • Referrer information

  • Typed URLs vs. clicked links

  • Search queries


Chrome/Edge (Chromium) Browser History

Database Location:

Database Format: SQLite

Key Tables:

Table
Description
Key Columns

urls

All visited URLs

id, url, title, visit_count, typed_count, last_visit_time

visits

Individual visit records

id, url (FK), visit_time, from_visit, transition

visit_source

Source of visit

id, source

downloads

Downloaded files

id, current_path, target_path, start_time, end_time, received_bytes, total_bytes, state, danger_type, opened

downloads_url_chains

Download referrer chain

id, chain_index, url

keyword_search_terms

Search queries

keyword_id, url_id, term, normalized_term

Collection:

Analysis - Using DB Browser for SQLite:

Using BrowsingHistoryView (NirSoft):

Using Hindsight (Python Tool):


Firefox Browser History

Database Location:

Database Format: SQLite

Key Tables:

Table
Description
Key Columns

moz_places

URLs visited

id, url, title, visit_count, last_visit_date, typed, description

moz_historyvisits

Individual visits

id, place_id (FK), visit_date, from_visit, visit_type

moz_bookmarks

Bookmarks

id, type, fk (place_id), title, dateAdded, lastModified

moz_annos

Annotations (downloads in FF26+)

id, place_id, anno_attribute_id, content, dateAdded

moz_anno_attributes

Annotation types

id, name

moz_inputhistory

Form inputs/autocomplete

place_id, input, use_count

Collection:

Analysis - SQL Queries:

Visit Types (Firefox):

Type
Description

1

Link followed

2

Typed URL

3

Bookmark

4

Embedded (iframe, image)

5

Permanent redirect

6

Temporary redirect

7

Download

8

Framed link


Investigation Workflows - Browser History

1. Malicious Site Identification:

2. Phishing Investigation:

3. Timeline Construction:

4. Search Query Analysis:

Red Flags:


πŸ“₯ Download History Analysis

Overview

Purpose: Track all files downloaded via browser, including malware, documents, tools

Key Information:

  • Downloaded file name

  • Original file name (before rename)

  • Download URL (source)

  • Referrer URL (how user got to download)

  • Download start time

  • Download end time

  • File size (total and received)

  • Download state (complete, interrupted, canceled)

  • Danger type (malware warning)

  • File system location

  • Opened status (was file executed?)


Chrome/Edge Download History

Location: Same History database as browsing history

Key Tables:

downloads table:

downloads_url_chains table:

Analysis - SQL Queries:


Firefox Download History

Location (versions):

Firefox 3-25:

Firefox 26+:

Analysis - Firefox 26+ (places.sqlite):


Investigation Workflows - Downloads

1. Malware Download Investigation:

2. Phishing Document Downloads:

3. Data Exfiltration Upload Detection:

4. Timeline Correlation:

Red Flags:


🌐 Internet Explorer/Edge File Access

WebCache Database

Overview:

  • Purpose: IE/Edge cache includes file:/// protocol access

  • Forensic Value: Tracks local and network file access even if not opened in browser

  • Persists: Even on Windows 11 without IE installed

  • Location: WebCacheV01.dat (ESE database)

Location:

What's Tracked:

Collection:

Analysis:

Using ESEDatabaseView (NirSoft):

Using BrowsingHistoryView (NirSoft):

Investigation Workflows:

1. Local File Access:

2. Network Share Access:

3. USB Drive Access:

4. Deleted File Evidence:


πŸ“§ Email Attachments Investigation

Overview

Key Statistic: 80% of email data stored as attachments

Forensic Value:

  • Phishing investigation

  • Malware delivery

  • Data exfiltration

  • Intellectual property theft

  • Communication analysis


Microsoft Outlook

File Formats:

Format
Description
Use Case

PST

Personal Storage Table

User's local email archive

OST

Offline Storage Table

Cached Exchange mailbox

Locations:

Collection:

Analysis:

Using Outlook (If Available):

Using SysTools Outlook PST Viewer (Free):

Using libpff (Python):

Using KAPE with Outlook Module:


Investigation Workflows - Email Attachments

1. Phishing Investigation:

2. Macro-Enabled Document Tracking:

3. Data Exfiltration:

4. Timeline Construction:


OLK Temporary Attachments

Overview:

  • When user opens attachment, copied to temp location

  • Remains until Outlook closed or attachment deleted

  • Can recover recently opened attachments

Location:

Collection & Analysis:

Investigation Use:


πŸ”„ Cross-Browser Analysis

Multi-Browser Investigation

Scenario: User may use multiple browsers (work = Edge, personal = Chrome)

Comprehensive Collection:

Unified Timeline Creation

Goal: Combine all browser activity into single timeline

Using BrowsingHistoryView:

Manual Correlation:


πŸ“š Investigation Playbooks

Playbook 1: Malware Download Investigation

Objective: Investigate suspected malware download and execution

Phase 1: Initial Indicators (15 min)

Phase 2: Download Detection (30 min)

Phase 3: Source Analysis (30 min)

Phase 4: File Analysis (45 min)

Phase 5: Execution Evidence (45 min)

Phase 6: Post-Execution Analysis (60 min)

Phase 7: Timeline & Reporting (30 min)


Playbook 2: Phishing Investigation

Objective: Investigate phishing email leading to credential theft or malware

Phase 1: Email Identification (20 min)

Phase 2: Link Analysis (30 min)

Phase 3: Attachment Analysis (45 min)

Phase 4: User Actions (45 min)

Phase 5: Credential Harvesting Check (30 min)

Phase 6: Impact Assessment (45 min)


Playbook 3: Data Exfiltration via Web

Objective: Detect data theft via web uploads

Phase 1: Baseline Activity (30 min)

Phase 2: File Access Detection (45 min)

Phase 3: Browser Activity Analysis (60 min)

Phase 4: Upload Detection (60 min)

Phase 5: Correlation (45 min)

Phase 6: External Evidence (varies)


πŸ› οΈ Tool Reference

Browser Analysis Tools

BrowsingHistoryView - NirSoft (Windows)

DB Browser for SQLite (Cross-platform)

Hindsight - Python Tool

Dumpzilla - Firefox Analysis


Email Analysis Tools

OutlookView Tools - NirSoft

Kernel PST Viewer - Free

libpff - Python Library


Collection Tools

KAPE - Kroll Artifact Parser and Extractor

FTK Imager


πŸ“Š Quick Reference Cards

Browser Database Comparison

Browser
Database
Format
History Table
Downloads Table
Location

Chrome

History

SQLite

urls, visits

downloads, downloads_url_chains

%LOCALAPPDATA%\Google\Chrome\User Data<Profile>\

Edge

History

SQLite

urls, visits

downloads, downloads_url_chains

%LOCALAPPDATA%\Microsoft\Edge\User Data<Profile>\

Firefox

places.sqlite

SQLite

moz_places, moz_historyvisits

moz_annos

%APPDATA%\Mozilla\Firefox\Profiles<random>.default\

IE/Edge Legacy

WebCacheV01.dat

ESE

Container_#

Container_#

%LOCALAPPDATA%\Microsoft\Windows\WebCache\

Time Conversion Reference

Chrome/Edge Timestamps:

Firefox Timestamps:

Investigation Time Estimates

Task
Estimated Time

Quick download history check

10-15 min

Comprehensive browser history analysis

30-60 min

Multi-browser correlation

45-90 min

Malware download investigation

2-3 hours

Phishing investigation

2-4 hours

Email attachment analysis

1-2 hours

Data exfiltration investigation

3-6 hours

Complete web activity timeline

4-8 hours


πŸŽ“ Pro Tips

Cross-Artifact Correlation Strategy

Red Flag Summary

Common Pitfalls

Timeline Reconstruction Tips


Use this guide for comprehensive web-based investigation. Remember: Browser artifacts + file system artifacts + execution artifacts = complete picture!

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