Accelerate your SASE deployment with the SASE Week Backstage Series. Explore sessions

close
close
  • Why Netskope chevron

    Changing the way networking and security work together.

  • Our Customers chevron

    Netskope serves more than 3,400 customers worldwide including more than 30 of the Fortune 100

  • Our Partners chevron

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

A Leader in SSE.
Now a Leader in Single-Vendor SASE.

Learn why Netskope debuted as a leader in the 2024 Gartner® Magic Quadrant™️ for Single-Vendor Secure Access Service Edge

Get the report
Customer Visionary Spotlights

Read how innovative customers are successfully navigating today’s changing networking & security landscape through the Netskope One platform.

Get the eBook
Customer Visionary Spotlights
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
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
Introducing the Netskope One Platform

Netskope One is a cloud-native platform that offers converged security and networking services to enable your SASE and zero trust transformation.

Learn about Netskope One
Abstract with blue lighting
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
NewEdge
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
Aerial view of a city
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
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 secure access service edge (SASE)

  • Events and 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

The Future of Security: Quantum, AI, and Macro-political Change
Emily Wearmouth and Max Havey speak with Netskope CEO Sanjay Beri and CTO Krishna Narayanaswamy about the future of security.

Play the podcast Browse all podcasts
The Future of Security: Quantum, AI, and Macro-political Change
Latest Blogs

Read how Netskope can enable the Zero Trust and SASE journey through secure access service edge (SASE) capabilities.

Read the blog
Sunrise and cloudy sky
SASE Week 2024 On-Demand

Learn how to navigate the latest advancements in SASE and zero trust and explore how these frameworks are adapting to address cybersecurity and infrastructure challenges

Explore sessions
SASE Week 2024
What is SASE?

Learn about the future convergence of networking and security tools in today’s cloud dominant business model.

Learn about SASE
  • Company chevron

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

  • Careers chevron

    Join Netskope's 3,000+ amazing team members building the industry’s leading cloud-native security platform.

  • Customer Solutions chevron

    We are here for you and with you every step of the way, ensuring your success with Netskope.

  • Training and Accreditations chevron

    Netskope training will help you become a cloud security expert.

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
Help shape the future of cloud security

At Netskope, founders and leaders work shoulder-to-shoulder with their colleagues, even the most renowned experts check their egos at the door, and the best ideas win.

Join the team
Careers at Netskope
Netskope’s talented and experienced Professional Services team provides a prescriptive approach to your successful implementation.

Learn about Professional Services
Netskope Professional Services
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

CloudSquirrel Malware Squirrels Away Sensitive User Data Using Popular Cloud Apps

Jul 15 2016
Tags
Cloud Best Practices
Cloud Malware
Cloud Security
CloudSquirrel
Netskope Threat Research Labs
Tools and Tips
Vulnerability Advisory

Netskope has discovered a malware campaign that takes advantage of multiple cloud apps throughout the kill chain. The campaign, which we have dubbed “CloudSquirrel,” has been in operation since June 2016 and has the intention of stealing and exfiltrating user data within the Outlook address book and, more importantly, usernames and corresponding passwords for email accounts configured in any of the email clients.

Likely originating in Brazil (based on names and parameters), CloudSquirrel is written in Java and is being distributed using ServInt’s Jelastic platform-as-a-service(PaaS). Jelastic redirects to the CloudApp collaboration platform which, in turn, uses Amazon AWS for its backend cloud services. This cloud malware actively uses Dropbox for its command and control communications.

We have observed the CloudSquirrel attack arriving via an email phishing attack. This attack email attempts to trick its victim into opening it with a “tax invoice” or other important-sounding link. Once open, CloudSquirrel infects users by downloading additional malicious encrypted payloads via a JAR file. Those can include information and password stealers. Once the malware establishes a connection with its command and control hosted in Dropbox, it’s commands masquerade as plain text files with fake extensions like .mp4, .wmv, .png, .dat, and .wma.

At this point, CloudSquirrel receives instructions to find and exfiltrate information both about users’ machines as well as account data such as usernames and passwords configured in native email clients.

Here is the redirect path that CloudSquirrel uses.

cloudsquirrel-redirect-path

Summary Observations

Our observation is that CloudSquirrel and other malware authors are aggressively using cloud applications in various stages of the malware attack kill chain. The CloudSquirrel campaign highlights the use of cloud applications for hosting drive-by-download files and, most importantly, to host command and control configuration data. A significant motivation for malware authors to use cloud applications (especially mainstream ones) is that many enterprises lack visibility into SSL traffic by traditional perimeter security vendors like firewalls and proxies. Enterprises – many of whom need to offer access to popular cloud services – are between a rock and a hard place, and often forced to allow these services in the first place, or at least make exceptions for them if blocked. This makes popular cloud services especially susceptible to use by malicious actors in the malware kill chain.

What Should You Do?

Netskope detects CloudSquirrel and other malware in and en route to cloud services. We recommend doing the following:

  • Detect and remediate all malware in sanctioned cloud apps
  • Detect and remediate all malware being downloaded from unsanctioned cloud apps
  • Actively track usage of unsanctioned instances of trusted cloud apps and enforce cloud DLP policies to control files and data entering and leaving your corporate environment
  • Regularly back up and turn on versioning for critical content in cloud apps
  • Disable macros in all Microsoft Office programs
  • Administrators should block macros by default via a group policy
  • Warn users to avoid opening untrusted attachments regardless of their extension or filename
  • Keep systems and antivirus updated with the latest releases and patches

We have also worked with the cloud application providers to take down the necessary data related to the malicious user accounts and files. We will be publishing a detailed technical blog on CloudSquirrel soon.

author image
Ashwin Vamshi
Ashwin Vamshi is a Security Researcher with innate interest in targeted attacks and malwares using cloud services.

Stay informed!

Subscribe for the latest from the Netskope Blog