| name | performing-cloud-storage-forensic-acquisition |
| description | Perform forensic acquisition and analysis of cloud storage services including Google Drive, OneDrive, Dropbox, and Box by collecting both API-based remote data and local sync client artifacts from endpoint devices. |
| domain | cybersecurity |
| subdomain | digital-forensics |
| tags | - cloud-forensics - google-drive - onedrive - dropbox - box - cloud-acquisition - api-forensics - sync-client - endpoint-artifacts - magnet-axiom |
| version | '1.0' |
| author | mahipal |
| license | Apache-2.0 |
| nist_ai_rmf | - MEASURE-2.7 - MAP-5.1 - MANAGE-2.4 |
| atlas_techniques | - AML.T0070 - AML.T0066 - AML.T0082 |
| nist_csf | - RS.AN-01 - RS.AN-03 - DE.AE-02 - RS.MA-01 |
Performing Cloud Storage Forensic Acquisition
Overview
Cloud storage forensic acquisition involves collecting digital evidence from services like Google Drive, OneDrive, Dropbox, and Box through both API-based remote acquisition and local endpoint artifact analysis. Modern investigations must address the challenge that cloud-synced files may exist in multiple states: locally synchronized, cloud-only (on-demand), cached, and deleted. Endpoint devices that have synchronized with cloud storage contain a wealth of metadata about locally synced files, files present only in the cloud, and even deleted items recoverable from cache folders. API-based acquisition using service-specific APIs provides direct access to remote data with valid credentials and proper legal authorization.
When to Use
- When conducting security assessments that involve performing cloud storage forensic acquisition
- When following incident response procedures for related security events
- When performing scheduled security testing or auditing activities
- When validating security controls through hands-on testing
Prerequisites
- Legal authorization (warrant, consent, or corporate policy) for cloud data access
- Valid user credentials or administrative access tokens
- Magnet AXIOM Cloud, Cellebrite Cloud Analyzer, or equivalent tool
- KAPE with cloud storage target files
- Python 3.8+ with google-api-python-client, msal, dropbox SDK
- Network connectivity for API-based acquisition
Acquisition Methods
Method 1: API-Based Remote Acquisition
Google Drive API Acquisition
from google.oauth2.credentials import Credentials
from googleapiclient.discovery import build
from googleapiclient.http import MediaIoBaseDownload
import io
import os
import json
from datetime import datetime
class GoogleDriveForensicAcquisition:
"""Forensically acquire files and metadata from Google Drive via API."""
def __init__(self, credentials_path: str, output_dir: str):
self.creds = Credentials.from_authorized_user_file(credentials_path)
self.service = build("drive", "v3", credentials=self.creds)
self.output_dir = output_dir
os.makedirs(output_dir, exist_ok=True)
self.acquisition_log = []
def list_all_files(self, include_trashed: bool = True) -> list:
"""List all files including trashed items."""
files = []
page_token = None
query = "" if include_trashed else "trashed = false"
while True:
results = self.service.files().list(
q=query,
pageSize=1000,
fields="nextPageToken, files(id, name, mimeType, size, "
"createdTime, modifiedTime, trashed, trashedTime, "
"owners, sharingUser, permissions, md5Checksum, "
"parents, webViewLink, driveId)",
pageToken=page_token
).execute()
files.extend(results.get("files", []))
page_token = results.get("nextPageToken")
if not page_token:
break
return files
def download_file(self, file_id: str, file_name: str, mime_type: str) -> str:
"""Download a file from Google Drive preserving forensic integrity."""
output_path = os.path.join(self.output_dir, file_name)
if mime_type.startswith("application/vnd.google-apps"):
export_formats = {
"application/vnd.google-apps.document": "application/pdf",
"application/vnd.google-apps.spreadsheet": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
"application/vnd.google-apps.presentation": "application/pdf",
}
export_mime = export_formats.get(mime_type, "application/pdf")
request = self.service.files().export_media(fileId=file_id, mimeType=export_mime)
else:
request = self.service.files().get_media(fileId=file_id)
with io.FileIO(output_path, "wb") as fh:
downloader = MediaIoBaseDownload(fh, request)
done = False
while not done:
_, done = downloader.next_chunk()
self.acquisition_log.append({
"timestamp": datetime.utcnow().isoformat(),
"file_id": file_id,
"file_name": file_name,
"output_path": output_path,
"action": "downloaded"
})
return output_path
def get_activity_log(self, file_id: str) -> list:
"""Retrieve activity/revision history for a specific file."""
revisions = self.service.revisions().list(
fileId=file_id,
fields="revisions(id, modifiedTime, lastModifyingUser, size, md5Checksum)"
).execute()
return revisions.get("revisions", [])
def export_acquisition_report(self) -> str:
"""Export acquisition log for chain of custody documentation."""
report_path = os.path.join(self.output_dir, "acquisition_log.json")
with open(report_path, "w") as f:
json.dump({
"acquisition_start": self.acquisition_log[0]["timestamp"] if self.acquisition_log else None,
"acquisition_end": datetime.utcnow().isoformat(),
"total_files": len(self.acquisition_log),
"entries": self.acquisition_log
}, f, indent=2)
return report_path
OneDrive / Microsoft 365 API Acquisition
import msal
import requests
import os
import json
from datetime import datetime
class OneDriveForensicAcquisition:
"""Forensically acquire files and metadata from OneDrive via Microsoft Graph API."""
def __init__(self, client_id: str, tenant_id: str, client_secret: str, output_dir: str):
self.output_dir = output_dir
os.makedirs(output_dir, exist_ok=True)
authority = f"https://login.microsoftonline.com/{tenant_id}"
self.app = msal.ConfidentialClientApplication(
client_id, authority=authority, client_credential=client_secret
)
token_result = self.app.acquire_token_for_client(
scopes=["https://graph.microsoft.com/.default"]
)
self.access_token = token_result.get("access_token")
self.headers = {"Authorization": f"Bearer {self.access_token}"}
self.base_url = "https://graph.microsoft.com/v1.0"
def list_user_files(self, user_id: str) -> list:
"""List all files in user's OneDrive."""
url = f"{self.base_url}/users/{user_id}/drive/root/children"
files = []
while url:
response = requests.get(url, headers=self.headers)
data = response.json()
files.extend(data.get("value", []))
url = data.get("@odata.nextLink")
return files
def download_file(self, user_id: str, item_id: str, filename: str) -> str:
"""Download a file from OneDrive."""
url = f"{self.base_url}/users/{user_id}/drive/items/{item_id}/content"
response = requests.get(url, headers=self.headers, stream=True)
output_path = os.path.join(self.output_dir, filename)
with open(output_path, "wb") as f:
for chunk in response.iter_content(chunk_size=8192):
f.write(chunk)
return output_path
def get_deleted_items(self, user_id: str) -> list:
"""Retrieve items from OneDrive recycle bin."""
url = f"{self.base_url}/users/{user_id}/drive/special/recyclebin/children"
response = requests.get(url, headers=self.headers)
return response.json().get("value", [])
Method 2: Local Endpoint Artifact Collection
KAPE Targets for Cloud Storage
# Collect all cloud storage artifacts using KAPE
kape.exe --tsource C: --tdest C:\Output\CloudArtifacts --target GoogleDrive,OneDrive,Dropbox,Box
# OneDrive artifacts
# %USERPROFILE%\AppData\Local\Microsoft\OneDrive\logs\
# %USERPROFILE%\AppData\Local\Microsoft\OneDrive\settings\
# %USERPROFILE%\OneDrive\
# Google Drive artifacts
# %USERPROFILE%\AppData\Local\Google\DriveFS\
# Contains metadata SQLite databases and cached files
# Dropbox artifacts
# %USERPROFILE%\AppData\Local\Dropbox\
# %USERPROFILE%\Dropbox\.dropbox.cache\
# Contains filecache.dbx (encrypted SQLite), host.dbx, config.dbx
OneDrive Local Database Analysis
import sqlite3
import os
def analyze_onedrive_sync_engine(db_path: str) -> list:
"""Analyze OneDrive SyncEngineDatabase for file metadata."""
conn = sqlite3.connect(db_path)
cursor = conn.cursor()
cursor.execute("""
SELECT fileName, fileSize, lastChange,
resourceID, parentResourceID, eTag
FROM od_ClientFile_Records
ORDER BY lastChange DESC
""")
files = []
for row in cursor.fetchall():
files.append({
"filename": row[0],
"size": row[1],
"last_change": row[2],
"resource_id": row[3],
"parent_id": row[4],
"etag": row[5]
})
conn.close()
return files
Cloud Storage Artifacts Summary
| Service | Local Database | Cache Location | Log Files |
|---|
| OneDrive | SyncEngineDatabase.db | %LOCALAPPDATA%\Microsoft\OneDrive\cache\ | %LOCALAPPDATA%\Microsoft\OneDrive\logs\ |
| Google Drive | metadata_sqlite_db | %LOCALAPPDATA%\Google\DriveFS{account}\content_cache\ | %LOCALAPPDATA%\Google\DriveFS\Logs\ |
| Dropbox | filecache.dbx (encrypted) | %APPDATA%\Dropbox.dropbox.cache\ | %APPDATA%\Dropbox\logs\ |
| Box | sync_db | %LOCALAPPDATA%\Box\Box\cache\ | %LOCALAPPDATA%\Box\Box\logs\ |
References
Example Output
$ python3 cloud_forensic_acquire.py --provider google-drive --auth /tokens/gdrive_token.json \
--user [email protected] --output /acquisition/gdrive
Cloud Storage Forensic Acquisition Tool v3.2
==============================================
Provider: Google Drive
Account: [email protected]
Start Time: 2024-01-19 08:00:15 UTC
Auth Method: Admin SDK (domain-wide delegation)
[+] Enumerating files...
Total files: 2,345
Total folders: 178
Shared with me: 456
Trashed items: 89 (included in acquisition)
Total size: 14.7 GB
[+] Acquiring file contents...
Downloaded: 2,345 / 2,345 [████████████████████████████████] 100%
Errors: 0
Elapsed: 18m 32s
[+] Acquiring metadata...
File metadata: 2,345 entries
Revision history: 8,912 revisions across 1,234 files
Sharing permissions: 3,456 permission entries
Activity log: 12,345 events
[+] Acquiring trashed items...
Recovered: 89 / 89 items (234 MB)
--- Acquisition Log ---
Timestamp (UTC) | Action | File | Size | SHA-256
2024-01-19 08:00:45 | Downloaded | /My Drive/Finance/Q4_Report.xlsm | 245 KB | 7a3b8c9d...
2024-01-19 08:00:46 | Downloaded | /My Drive/Finance/Budget_2024.xlsx | 1.2 MB | 8b4c9d0e...
...
2024-01-19 08:02:12 | Trash-Recovered | /Trash/employee_list_full.csv | 4.5 MB | 9c5d0e1f...
2024-01-19 08:02:13 | Trash-Recovered | /Trash/network_diagram_v3.vsdx | 2.1 MB | 0d6e1f2a...
2024-01-19 08:02:14 | Trash-Recovered | /Trash/credentials_backup.kdbx | 128 KB | 1e7f2a3b...
--- Sharing Analysis ---
Files Shared Externally:
/My Drive/Finance/Q4_Report.xlsm → [email protected] (2024-01-16 03:10 UTC)
/My Drive/HR/employee_list_full.csv → [email protected] (2024-01-16 03:12 UTC)
/My Drive/IT/network_diagram_v3.vsdx → anonymous (link sharing, 2024-01-16 03:15 UTC)
--- Revision History (Suspicious) ---
File: /My Drive/Finance/Q4_Report.xlsm
Rev 1: 2024-01-10 09:00:00 UTC (245 KB) - Original
Rev 2: 2024-01-15 14:35:00 UTC (248 KB) - Modified (macro added)
Rev 3: 2024-01-16 03:05:00 UTC (245 KB) - Reverted (macro removed - anti-forensics)
Acquisition Summary:
Files acquired: 2,345 (14.7 GB)
Trashed items: 89 (234 MB)
Revisions: 8,912
Chain of custody hash (full archive):
SHA-256: a1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4e5f6a1b2
Output directory: /acquisition/gdrive/
Acquisition log: /acquisition/gdrive/acquisition_log.csv
Completion Time: 2024-01-19 08:18:47 UTC
