Netskope extends data protection leadership with acquisition of Dasera. Read the press release

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 dedicated service and support professionals will ensure you successful deploy and experience the full value of our platform.

Go to Customer Solutions
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

Netskope Threat Coverage: CrossLock Ransomware

May 02 2023

Summary

CrossLock is a ransomware group that emerged in April 2023, targeting a large digital certifier company in Brazil. This ransomware was written in Go, which has also been adopted by other ransomware groups, including Hive, due to the cross-platform capabilities offered by the language. CrossLock operates in the double-extortion scheme, by threatening to leak stolen data on a website hosted on the deep web if the ransom isn’t paid by the victim.

Deep web site where CrossLock is posting its targets and leaking stolen data.

In this blog post, we will show how the CrossLock ransomware works.

Analysis 

The CrossLock ransomware was developed in the Go programming language, and was likely compiled on April 16, 2023, which is the same day where the attackers added the Brazilian digital certifier in their deep web site.

CrossLock binary details.

Attackers can use CrossLock to infect not only a local system, but also a remote system by using their custom parameters, which are described below:

ParameterDescription
--path, -PEncrypt the specified path
--host, -HRemote system to run CrossLock (which can be a DNS or an IP address)
--domain, -dThe domain name (default is “.”)
--user, -uUsername used to authenticate in the remote system
--pwd, -pPassword of the user specified in “-u” or “--user”
--uac, -ubIf specified, tries to bypass Windows UAC to run with elevated privileges

Like other ransomware families, such as BlackCat, CrossLock offers a “help” menu to provide instructions on how to use these parameters. They even included an example on how to execute CrossLock on a remote system and encrypt the entire file directory.

CrossLock help menu.

When executed, CrossLock outputs what it’s doing to a console. Also, the attacker left a few debug logs enabled, so it’s possible to get more insights of what it’s doing by just looking at the output.

Debug logs outputted by CrossLock ransomware.

To avoid detection, CrossLock bypasses the Event Tracing for Windows (ETW), which is a mechanism that provides system and application logs that can be used by developers for debugging. This is done through a common API hooking technique, by patching functions EtwEventRegister, EtwNotificationRegister, EtwEventWriteFull, and EtwEventWrite on “ntdll.dll”.

CrossLock ransomware patching ETW functions.

CrossLock has a hardcoded list of services and processes that it tries to stop before encrypting files, which is a common practice among ransomware families. First, it tries to stop services related to backup services, databases, and security software. Then, it tries to stop a series of processes. The complete list of services and processes it tries to stop can be found in our GitHub repository.

CrossLock loading the name of processes to stop.

CrossLock also runs additional commands to delete Windows Shadow Copies using vssadmin, and to disable boot recovery using bcdedit.

Additional commands CrossLock ransomware runs.

If no path was specified via “–path” or “-P” parameters, CrossLock starts crawling and encrypting files.

CrossLock ransomware output logs.

Like other ransomware families, CrossLock does not encrypt files that contain specific extensions or that are under specific folders, such as Windows, Program Files, and ProgramData. This is a common practice that avoids encrypting files that can corrupt the system. The list of extensions CrossLock ignores can be found in our GitHub repository.

Some of the extensions CrossLock will ignore.

To encrypt files, CrossLock combines Curve25519 and ChaCha20 algorithms, which are implemented through Go packages.

Go packages related to encryption within CrossLocker.

CrossLock adds the extension “.crlk” to encrypted files.

Files encrypted by CrossLock ransomware.

The ransom note contains the name of the company that was targeted and instructions to contact the attackers via tox chat to ne