The Future of Zero Trust and SASE is Now! Register now

The platform of the future is Netskope

Intelligent Security Service Edge (SSE), Cloud Access Security Broker (CASB), Cloud Firewall, Next Generation Secure Web Gateway (SWG), and Private Access for ZTNA built natively into a single solution to help every business on its journey to Secure Access Service Edge (SASE) architecture.

Go to Products Overview
Netskope video
Next Gen SASE Branch is hybrid — connected, secured, and automated

Netskope Next Gen SASE Branch converges Context-Aware SASE Fabric, Zero-Trust Hybrid Security, and SkopeAI-powered Cloud Orchestrator into a unified cloud offering, ushering in a fully modernized branch experience for the borderless enterprise.

Learn about Next Gen SASE Branch
People at the open space office
Designing a SASE Architecture For Dummies

Get your complimentary copy of the only guide to SASE design you’ll ever need.

Get the eBook
Embrace a Secure Access Service Edge (SASE) architecture

Netskope NewEdge is the world’s largest, highest-performing security private cloud and provides customers with unparalleled service coverage, performance and resilience.

Learn about NewEdge
Your Network of Tomorrow

Plan your path toward a faster, more secure, and more resilient network designed for the applications and users that you support.

Get the white paper
Your Network of Tomorrow
Netskope Cloud Exchange

The Netskope Cloud Exchange (CE) provides customers with powerful integration tools to leverage investments across their security posture.

Learn about Cloud Exchange
Netskope video
Make the move to market-leading cloud security services with minimal latency and high reliability.

Learn about NewEdge
Lighted highway through mountainside switchbacks
Safely enable the use of generative AI applications with application access control, real-time user coaching, and best-in-class data protection.

Learn how we secure generative AI use
Safely Enable ChatGPT and Generative AI
Zero trust solutions for SSE and SASE deployments

Learn about Zero Trust
Boat driving through open sea
Netskope achieves FedRAMP High Authorization

Choose Netskope GovCloud to accelerate your agency’s transformation.

Learn about Netskope GovCloud
Netskope GovCloud
  • Resources chevron

    Learn more about how Netskope can help you secure your journey to the cloud.

  • Blog chevron

    Learn how Netskope enables security and networking transformation through security service edge (SSE).

  • Events & Workshops chevron

    Stay ahead of the latest security trends and connect with your peers.

  • Security Defined chevron

    Everything you need to know in our cybersecurity encyclopedia.

Security Visionaries Podcast

Cookies, Not Biscuits
Host Emily Wearmouthas sits down with experts David Fairman and Zohar Hod to discuss the past, present, and future of internet cookies.

Play the podcast
Podcast: Cookies, Not Biscuits
Latest Blogs

How Netskope can enable the Zero Trust and SASE journey through security service edge (SSE) capabilities.

Read the blog
Sunrise and cloudy sky
SASE Week 2023: Your SASE journey starts now!

Replay sessions from the fourth annual SASE Week.

Explore sessions
SASE Week 2023
What is Security Service Edge?

Explore the security side of SASE, the future of network and protection in the cloud.

Learn about Security Service Edge
Four-way roundabout
We help our customers to be Ready for Anything

See our Customers
Woman smiling with glasses looking out window
Netskope’s talented and experienced Professional Services team provides a prescriptive approach to your successful implementation.

Learn about Professional Services
Netskope Professional Services
The Netskope Community can help you and your team get more value out of products and practices.

Go to the Netskope Community
The Netskope Community
Secure your digital transformation journey and make the most of your cloud, web, and private applications with Netskope training.

Learn about Training and Certifications
Group of young professionals working
  • Company chevron

    We help you stay ahead of cloud, data, and network security challenges.

  • Why Netskope chevron

    Cloud transformation and work from anywhere have changed how security needs to work.

  • Leadership chevron

    Our leadership team is fiercely committed to doing everything it takes to make our customers successful.

  • Partners chevron

    We partner with security leaders to help you secure your journey to the cloud.

Supporting sustainability through data security

Netskope is proud to participate in Vision 2045: an initiative aimed to raise awareness on private industry’s role in sustainability.

Find out more
Supporting Sustainability Through Data Security
Highest in Execution. Furthest in Vision.

Netskope recognized as a Leader in the 2023 Gartner® Magic Quadrant™ for Security Service Edge.

Get the report
Netskope recognized as a Leader in the 2023 Gartner® Magic Quadrant™ for Security Service Edge.
Thinkers, builders, dreamers, innovators. Together, we deliver cutting-edge cloud security solutions to help our customers protect their data and people.

Meet our team
Group of hikers scaling a snowy mountain
Netskope’s partner-centric go-to-market strategy enables our partners to maximize their growth and profitability while transforming enterprise security.

Learn about Netskope Partners
Group of diverse young professionals smiling

Leaky Images: Accidental Exposure and Malware in Google Photos and Hangouts

Sep 29 2020

Did you know that the default link sharing option in Google Photos allows anyone with the link to view the files and all images shared in Google Hangouts that are publicly accessible? In this edition of our leaky app series, we will cover how image link sharing in Google Hangouts and Google Photos can lead to the accidental public exposure of sensitive data. We will also look at the threat detection capabilities of Google Photos and Google Hangouts. Whereas files uploaded to Google Drive are scanned for malicious content, no such scanning occurs in Photos or Hangouts. 

This post is part of a series highlighting data exposure concerns in Google Calendar, Google Groups, Google link sharing, Zendesk, and O365 link sharing. We will highlight the exposure concerns, detection gaps in Google services, Netskope’s CTEP capability, and a method for data exfiltration.

Google Hangouts

In Google Hangouts, users can share images and videos alongside their chat conversations. Every image shared in Google Hangouts generates a public link, as shown in Figure 1.

Screenshot of link sharing options for images in Google Hangouts
Figure 1: Google Hangouts image links

The generated link is accessible to anyone without any authentication. On top of this, the link remains valid indefinitely, unless the image is deleted from the Google Album Archive.  Furthermore, this is true even of images uploaded when the “conversation history” is disabled. Even though the conversation itself is not retained, the images shared while the history is disabled are.

Google Photos

Alongside Google Hangouts, Google Photos also allows users to upload and share photos and videos. The photos and videos shared have the default permission to let anyone with the link to see the photos or albums as shown in Figure 2.

Screenshot showing the default link sharing settings for Google Photos
Figure 2: Google Photos default link sharing option

Google Photos also allows a user to share the photos to selected people, share via Facebook and Twitter, and copy links as shown in Figure 3.

Screenshot of the sharing options for Google Photos
Figure 3: Google Photo sharing options

When you use “copy link” and share the link, you relinquish control over who can access your files—anyone who gets their hands on a link can access a file, whether you intended them to or not. We recommend sharing sensitive images only to specific users or uploading the files to Google Drive with restricted link sharing as an alternative to avoid accidental exposure.

Google Hangouts and Google Photos link sharing 

The default link sharing settings in Google Hangouts and Google Photos can lead to accidental exposure of sensitive internal data to the public Internet. The links these services generate can be accessed by anyone and do not require authentication. Though this won’t make the data indexable by search engines, it can likely pose exposure concerns in the following ways:

  • Anyone, inside or outside of your domain, with whom you didn’t intend to share the image, can access the image if they get their hands on the link.
  • Users within your organization can continue to access the images after they leave.

To take it a step further, a malicious insider can share snapshots of private keys, passwords, tokens, or sensitive documents. Because these are public links, they can be downloaded by anyone at any time with little audit trail, making them a useful channel for data exfiltration.

When sharing sensitive content, we recommend restricting access to specific users in Google Photos to avoid accidental exposure. Users should not share sensitive information via  Hangouts or via the “copy link” option in Google Photos. Any sensitive images already shared via Hangouts can be deleted from the Google Album Archive and any public links can be removed in Google Photos. Netskope customers can create DLP rules to detect sensitive images that contain x-rays, passports, and other sensitive information, to prevent them from being uploaded to such apps.

Threat detection in Google Hangouts and Google Photos

As Google Hangouts and Google Photos provide file hosting via public and unauthenticated links, they can potentially be used to spread malware. Techniques used by attackers to embed malicious content images without affecting their appearance include:

Google Photos and Google Hangouts do not contain any native threat detection capabilities. We tested this detection capability by uploading and sharing a variety of malicious image files. To our surprise, none of the malicious files were detected or blocked by either service. An example of a malicious gif file uploaded to Google Hangouts is shown in Figure 4.

Screenshot showing malicious gif file uploaded to Google Hangouts
Figure 4: Malicious gif file uploaded to Google Hangouts

By comparison, the same files were detected by Google Drive. An example of one such alert is shown in Figure 5.

Screenshot showing Gooogle Drive detecting a malicious file
Figure 5: Google Drive detecting a malicious file

This clearly illustrates that the threat detection offered by Google varies from service-to-service. Netskope customers are protected from malicious content regardless of cloud app or service.  An example of an alert generated by Netskope for the same image hosted in Google Hangouts is shown in Figure 6. Netskope CTEP detected the malicious embedded VB Script and blocked the image.

Screenshot showing Google Hangouts detection of the malicious image by Netskope
Figure 6: Google Hangouts detection of the malicious image by Netskope


This edition of our leaky cloud apps series provided a detailed synopsis of how confidential information can get leaked through Google Hangouts and Google Photos leading to public exposure. The data can be copied, reused, and leveraged by adversaries and insiders to gain access to additional data and infrastructure. We recommend auditing link sharing options and restricting access to specific users in Google Photos to avoid accidental exposure. Users should not share sensitive images via Hangouts and/or via the “copy link” option in Google Photos.

Alongside the exposure concerns, we also detailed a detection gap in Google Photos and Hangouts, Netskope’s CTEP capability, and a method for data exfiltration. Cloud service providers have their own security controls, but they vary from service-to-service. Organizations need to have a threat protection service that works consistently across cloud apps to ensure they are fully protected. Netskope’s DLP and threat solutions detect sensitive images to prevent unwanted data exposure and provide comprehensive threat protection for all the cloud apps and services used by the enterprise.

author image
Ashwin Vamshi
Ashwin Vamshi is a Security Researcher with innate interest in targeted attacks and malwares using cloud services. He is primarily focusing in identifying new attack vectors and malwares, campaigns and threat actors using ‘cloud as an attack vector.’

Stay informed!

Subscribe for the latest from the Netskope Blog