The Complete Guide to Slack DLP (Data Loss Prevention) in 2025

Data loss can be severe, ranging from regulatory compliance violations to reputational damage and financial loss.

The 2017 Uber data breach exemplifies the risks associated with insufficient DLP measures. Hackers accessed Uber's software repository on GitHub by stealing credentials from an engineer's Slack account, exposing personal data for 57 million users. By acknowledging and proactively addressing the problem, organizations can maintain regulatory compliance and avoid financial and reputational damage.

With over 750K organizations relying on Slack, implementing Slack Data Loss Prevention (DLP) measures to safeguard sensitive information becomes crucial. 

This blog highlights the importance of robust security measures and vigilance in safeguarding our online assets and preventing unauthorized access. We will delve into the details of Slack’s compliance with strict data security standards like CCPA, GDPR, PCI, and HIPAA to safeguard users' sensitive information.

What is Slack DLP (Data Loss Prevention)?

Data Loss Prevention (DLP) safeguards confidential or sensitive information—such as credit card numbers, Personally Identifiable Information (PII), and API keys, passwords—from being shared outside of Slack. It achieves this by scanning messages and files for content that violates predefined policies. Slack DLP (Data Loss Prevention) refers to security solutions that prevent unauthorized sharing or leakage of sensitive data within Slack. It does the following:

1. Automated Data Protection: Scans messages, files, and attachments in Slack to detect and prevent exposure of sensitive information.
2. Sensitive Data Identification: Detects PII, PHI, PCI, confidential business information, and intellectual property.
3. Real-Time Monitoring: Monitors Slack channels, direct messages (DMs), private groups, and external workspaces for security risks.
4. Compliance Enforcement: Helps organizations comply with HIPAA, PCI-DSS, GDPR, SOC 2, and other regulatory requirements.
5. Risk Remediation: Blocks, redacts, alerts, or removes sensitive data to prevent accidental or malicious data leaks.
6. Integration with Security Tools: Works alongside SIEM, CASB, and other security solutions for a unified data protection strategy.
7. External Collaboration Control: Ensures secure communication with third-party guests and external Slack workspaces.

Why do I need a DLP solution for Slack?

Key Reasons for Implementing Slack DLP:

• Unstructured Data Exposure:
  • Employees often share sensitive data in Slack messages, files, and links without realizing the security risks.
  • Slack lacks built-in tools to scan, detect, and prevent sensitive data leakage.
• Compliance & Regulatory Requirements:
  • Organizations subject to HIPAA, PCI-DSS, GDPR, SOC 2, and CCPA must protect PII, PHI, and financial data.
  • Slack’s default security settings do not automatically enforce data protection policies for compliance.
• External Workspaces & Guest Users Risks:
  • Slack allows guest access and external workspaces, increasing the chances of data leaks to third parties.
  • Sensitive files and messages can be accidentally shared outside the organization without proper restrictions.
• File & Link Sharing Risks:
  • Users can upload files (PDFs, Excel, Word, images) containing sensitive information.
  • Shared Google Drive, Dropbox, OneDrive, and AWS links may grant unintended access to confidential data.
• Lack of Native Slack Security Controls:
  • No built-in data classification to track and protect confidential information.
  • No automated scanning for sensitive data in public/private channels and direct messages.
• Prevent Insider Threats & Accidental Sharing:
  • Employees may inadvertently share API keys, passwords, or company secrets in Slack.
  • Malicious insiders can exfiltrate data by sharing files or exporting Slack conversations.
• Security Team & Audit Challenges:
  • Security teams lack visibility into who is sharing sensitive data and where it is stored.
  • No audit logs or incident response mechanisms for real-time detection and mitigation.

In summary, a DLP solution is crucial for safeguarding sensitive information, ensuring compliance with legal requirements, and enhancing overall data security within your organization.

Does Slack have a built-in DLP?

No. Slack relies on third-party apps (like Strac) for DLP functionality, so a dedicated solution is crucial for HIPAA compliance. Strac is a Slack DLP partner.

If your organization needs to adhere to HIPAA regulations, it's essential to have a DLP solution in place when using Slack.

What sensitive information does Slack hold?

Slack can contain various types of sensitive information that require protection, including:

• Personally Identifiable Information (PII): This includes names, email addresses, phone numbers, and other identifiers that can be used to identify individuals.
• IP (Intellectual Property): Valuable company information, trade secrets, and proprietary data.
• PHI (Protected Health Information): Medical records and other health-related data governed by strict privacy regulations.
• PCI (Payment Card Industry data): Credit card numbers, bank routing numbers, account holder details, and more.
• Financial Information: Sensitive financial data such as CC numbers, bank account details, or any proprietary financial documents shared within the platform.
• Intellectual Property: Confidential company documents, project plans, or proprietary technology that could be detrimental if exposed to unauthorized parties.
• Health Information: For organizations in the healthcare sector, Slack may hold sensitive health records or personal health information (PHI) that is required to be protected under regulations like HIPAA.

Given that Slack retains data from paid accounts indefinitely and from free accounts for up to a year unless deleted by users or administrators, it is critical to implement robust DLP measures to manage this sensitive information effectively. 

Slack Connect and DLP

With Slack Connect's Data Loss Prevention (DLP) feature, securing cross-company collaboration just got easier. You can now, 

• minimize the risk of sharing sensitive and confidential information with external organizations,
• monitor all channels and direct messages sent and received by your organization's users, ensuring that nothing breaches your established policies, and
• control your data and collaborate with external partners confidently and seamlessly

But that’s not all, here are a few benefits of Slack Connect and DLP⬇️

1. Admin privileges

The organization's primary owners and members with admin system roles can assign DLP admin system roles to other members. DLP admins can enhance security by creating custom rules using regular expression (regex) format to effectively flag messages or files for administrative action.

They have the flexibility to choose whether to hide tombstone messages or files until they can be reviewed. This feature leads to an efficient review process, ensuring that potential violations are not overlooked. DLP admins play a crucial role in maintaining compliance by reviewing rule violations and taking appropriate action on flagged messages and files.

2. Security alerts

Managing alerts for policy violations in your organization has never been easier. With the Slack DLP dashboard, you'll receive instant alerts whenever a member sends a message that violates a DLP rule. From the dashboard, you can efficiently handle these alerts by archiving them, deleting the corresponding message, or restoring it if it was initially hidden. 

3. Seamless data management

Ensure seamless data management within your organization with advanced retention settings in Slack. Rest assured that messages and files sent by your members will be subject to your organization's retention policies. 

Any content received from individuals outside of your company will be handled based on their respective organization's retention settings. In addition, Slack’s message editing and deletion settings are tailored specifically for your organization. Only members of your team can edit or delete messages sent by them, ensuring complete control over communication within your workspace.

4. Powerful encryption

Starting September 2020, Enterprise Key Management (EKM) is now available for Slack Connect. This update ensures that messages and files sent by members of your organization are encrypted using your own keys. And here's the best part - if you're already an EKM customer, this encryption will also be applied retroactively to previous communications. If other companies are also EKM customers, any messages or files they send you will be encrypted with their keys. With EKM, you can ensure the utmost security and protection for all your communications on Slack Connect.

5. Content regulation

Organizations can now leverage e-discovery and data loss prevention (DLP) solutions to effectively review and regulate content across channels and DMs shared with individuals from other companies. 

The Discovery API allows all organizations to access and read content in channels and DMs shared with external parties. However, only messages and files sent by members of your own organization within a channel or DM can be edited or deleted using the Discovery API. While using user methods, the Discovery API will return the display names of members from external organizations. 

However, this information will not be displayed alongside the conversation history. Regardless of an organization's email display settings, email addresses of members from external organizations will be returned via Discovery API.

Essential functionalities for a DLP

When considering data loss prevention (DLP) functionalities for Slack, it is crucial to look for these essential features. 

1. Content analysis

The DLP solution should be able to scan messages, files, and other content shared within channels and direct messages. It should be able to analyze the content for sensitive information like personally identifiable information (PII), financial data, intellectual property, or any other confidential information. By ensuring a robust content scanning feature in your DLP solution for Slack, you can proactively identify and prevent potential data breaches or leaks. This ultimately helps safeguard your organization's reputation and ensures compliance with regulatory requirements.

2. Flexibility

Organizations should be free to establish and tailor DLP rules to meet their unique requirements for data security. Administrators should be able to establish guidelines and scenarios that result in policy breaches using specific patterns or keywords. It should also monitor policy violations and take appropriate actions.

3. Real-time alerts

The DLP solution should provide real-time alerts and notifications to notify administrators promptly of policy violations. This lets them immediately address the violation, minimizing data loss or exposure risks. Additionally, the automated actions offered by the DLP solution ensure consistent policy enforcement. Based on the severity of policy violations, these automated actions may include warning the user, blocking the message from being sent, or quarantining the content for review.

4. Actionable insights

DLP solutions should provide visibility into policy breaches, data leakage events, and trends to enable robust reporting and auditing capabilities. These insights help companies assess their situation and make well-informed decisions to improve it.

5. Slack DLP Integration with other tools

It should integrate seamlessly with other tools to improve enterprise data security options. It should ensure total security using data loss prevention solutions, security information and event management (SIEM) systems, or other applicable safety measures.

6. Customization

It should provide the option to add custom detectors, rules, keywords, regexes, and pre-built detectors that cover a wide range of data types. It should be able to scan files and messages from various file categories, including xls/xlsx, doc/docx, CSV, plain text, ppt/pptx, PDF, HTML, and others.

Does Slack have DLP Support for Pro and Business+ Plan?

No. Slack does not offer native DLP support for Pro and Business+ Plan

Does Slack have DLP Support for Enterprise Grid Plan?

Yes. Slack has DLP support for Enterprise Grid Plan. Please see below the limitations of Slack DLP.

Does DLP work on any Slack plan?

Many DLP solutions don’t support every Slack plan. Strac is the only DLP solution that supports all Slack plans - Free, Pro, Business+ and Enterprise Plans. Learn more.

What are the Slack Enterprise DLP Limitations?

Even for Enterprises, Slack's native DLP is not enough. It does not do the following:

1. Lack of File Content Scanning (Especially Images/PDFs)

Slack’s native DLP does not scan inside files for sensitive information—particularly images, screenshots, or PDFs with embedded images. It lacks the OCR or deep inspection needed to recognize hidden or unstructured data.

2. No Granular or Customizable Policies

Out of the box, Slack does not offer policy-based scanning tailored to specific channels, data elements, or user groups. Administrators cannot configure detailed rules, such as “only scan the #finance channel for bank account numbers.”

3. Inability to Redact Sensitive Message Content

Slack does not provide  redaction within messages. An admin may delete entire messages or set retention policies, but cannot mask just the sensitive portion (e.g., a credit card number) and leave the rest.

4. Inability to Redact Sensitive Files

Slack’s native DLP cannot redact or mask sensitive information within files. If a file contains protected data, Slack can only block or remove it entirely—not selectively remove or hide specific parts.

5. All-or-Nothing File Sharing Controls

Slack does not let you allow file sharing in certain contexts while blocking it in others. It’s mostly a binary setting—either you permit file sharing or you block it. Fine-grained controls (e.g., “Block sensitive files for Team A, but allow for Team B”) typically require third-party DLP or CASB solutions.

6. Limited (Regex-Based) Detection and No Unstructured Document Scanning

Slack’s built-in scanning primarily relies on pattern matching (like regex). It cannot analyze or extract text from complex, unstructured documents (e.g., PDFs, images, screenshots). For advanced classification and scanning, you need an external DLP or CASB integrated with Slack’s APIs.

What are the Drawbacks of Creating Your Own DLP Solution for Slack?

The primary disadvantages of implementing the described measures include:

1. Inadequate Visibility into Sensitive Files: From a security perspective, there's a blind spot regarding the quantity of sensitive files on Slack, including those shared internally and externally. This lack of insight is a significant risk as it prevents understanding the full scope of potentially exposed data.
2. Obscured Visibility of File Downloads: Leaders in business and security have no clear way to track who downloads or shares files, posing a risk to information security.
3. Dependence on Manual Monitoring: The task of regularly checking for suspicious activities heavily relies on the manual efforts of employees, requiring them to identify unusual patterns, which is not always reliable.
4. Resource-Intensive Training: Educating employees on recognizing suspicious behaviors demands a considerable investment of time and resources, with ongoing training necessary to maintain awareness.
5. Susceptibility to Errors: Despite training, the human capacity to accurately identify sensitive versus non-sensitive content at scale is limited and prone to errors, which can be costly if overlooked.
6. Lack of Comprehensive Coverage: The landscape of security threats is ever-evolving, making it impossible to train individuals to recognize every possible type of attack, thus leaving gaps in security coverage.

What does DLP detect?

1. DLP solutions should be capable of scanning a wide range of data types, including personally identifiable information (PII), protected health information (PHI), finance and payment card information (PCI), health data, networking information, and credentials & secrets (such as API keys and cryptographic keys).
2. Strac offers pre-built detectors that cover an extensive set of data types, industries, and geographies right out of the box. Additionally, Strac allows you to incorporate custom detectors, rules, keywords, and regexes.
3. Explore Strac's catalog of sensitive data elements to learn more.

Does DLP scan my entire Slack organization?

1. You should choose a DLP solution that scans both files and messages.
2. Strac supports a wide variety of file types, including but not limited to xls/xlsx, doc/docx, csv, plain text, ppt/pptx, PDF, HTML, and more.

Real-Life Slack Breach Examples

1. Uber’s Slack Takeover (2022)

In September 2022, Uber suffered a major breach where a hacker took control of their Slack workspace and sent messages to employees. The attacker gained access through social engineering, tricking an employee into approving a multi-factor authentication (MFA) request. Once inside Slack, they used the compromised account to post messages and access internal tools.

Key Takeaways:

Social engineering attacks are a significant risk in Slack environments.Strong authentication policies (such as phishing-resistant MFA) are necessary.DLP solutions should monitor for unusual user behavior, such as excessive file sharing or access to restricted channels.

2. Electronic Arts (EA) Data Breach via Slack (2021) In June 20

21, hackers stole 780GB of data from EA, including FIFA and Battlefield game source code. The attackers used Slack to manipulate an employee into handing over credentials, which they then used to breach internal systems.

Key Takeaways:

Slack is a common entry point for attackers due to its frequent use for internal communications.User education and monitoring are necessary to prevent phishing attempts.DLP tools should restrict the sharing of sensitive credentials and monitor for high-risk behavior.

3. Code Repositories & Credential Leaks in Slack

Security researchers have repeatedly found sensitive credentials, AWS keys, and internal database access details being shared within Slack channels, often by accident. This has led to unauthorized access and data exposure for many companies, including startups and Fortune 500 firms.

Key Takeaways:

Employees often accidentally share passwords, API keys, and sensitive files in Slack.Real-time scanning and redaction of sensitive data prevent unintended exposure.Automated policy enforcement can detect and block high-risk data before it spreads.

Best Practices for Slack Data Security

How Does Strac Help You Stay Compliant With Even the Toughest Benchmarks?

Maintaining data security compliance within Slack can be a daunting task. But with Strac, a powerful DLP (Data Loss Prevention) solution, you no longer have to do it alone. Strac provides comprehensive monitoring and visibility into your data and systems. 

By filtering data streams, it effectively restricts any suspicious or unidentified activity. It also enables you to log data for incident response and auditing purposes. Strac brings everything together to help prevent customer data from falling into the wrong hands. Compliance standards include GDPR, HIPAA, PCI, CCPA, and SOC 2.

Here are several ways to enhance your compliance requirements with Strac for Slack Connect filter policies:

• Quickly identify and safeguard sensitive data that requires protection and promptly address policy violations based on your unique compliance requirements.
• Establish an external sharing policy within your Slack Connect channels to configure individual rules. You can also utilize multiple policies simultaneously for maximum control within your Slack environment.
• Gain visibility into your channels. Understand who is connected to your organization via Slack Connect channels. Without a comprehensive view of these channels, your attack surface could quickly escalate beyond manageable levels.

How Does Strac DLP Secure Your Slack Data?

Protecting sensitive customer information is crucial for Slack users. With Strac, an advanced DLP software integrated into the Slack app, you can ensure account security and prevent unauthorized file sharing.

If your organization needs to adhere to compliance or regulations or from security incidents, it's essential to have a DLP solution in place when using Slack.

• One of the standout features of Strac is its redaction experience. It intelligently identifies and redacts/blocks sensitive customer data such as PII, PHI, or PCI within private channels, public channels, direct messages (DMs), and group direct messages, keeping important data confidential.
• Strac provides audit reports giving you full visibility and control over your data.
• Safeguarding sensitive information is crucial, so our catalog automatically detects and redacts potential risks. But that's not all – Strac, masks or removes sensitive messages and files while allowing authorized users to access them securely in the Strac UI Vault.
• In addition to safeguarding your data, Strac also prevents unauthorized file sharing on channels or through Slack Connect when configured. This means you have full control over who can access and share files within your workspace.
• The best part? Strac works seamlessly across all Slack channels and pricing plans, making it accessible for everyone. And with security and compliance officers receiving detailed audit reports on message access, you can rest assured that your data is safe. Check out how Strac can secure your Slack workspace.

Sensitive Data Types for Slack DLP

Strac offers extensive support for a wide array of sensitive data elements in global formats, covering identity details (such as driver’s licenses and passports), healthcare IDs, financial information, intellectual property, and more. Equipped with advanced detection and remediation capabilities, Strac delivers thorough data security and compliance across SaaS applications, cloud databases, AI platforms, and endpoint devices. This broad support empowers organizations to protect essential data efficiently. For a detailed list, check out Strac's blog on sensitive data elements.

Conclusion

When it comes to audits, meeting compliance requirements can be a challenging task. Many compliance regimes have open-ended requirements that need to be addressed. 

That's where implementing a SaaS Data Loss Prevention (DLP) solution can make all the difference. Strac offers a quick and easy step toward ensuring your organization has the right compliance in place for audits. By automating daily tasks and streamlining data protection processes, our DLP solution helps you meet compliance requirements efficiently.

What’s more? Strac’s powerful features can help you enhance the security of your sensitive information, ensuring seamless collaboration among team members. From preventing accidental data leaks to identifying potential risks, Strac offers a robust solution that helps safeguard your organization's valuable data. 

Explore more on Slack security:

• Slack HIPAA Compliance
• How to secure Slack?