A Comprehensive Overview of In-App Chat Scams: Part 2

14 min read Michael Carroll on Oct 29, 2023
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In-app chat scams are a large, yet often overlooked, vector for cybersecurity attacks. In-app chat has become such a large and integral part of the online economy, that we can easily take it for granted. Social media platforms, messaging apps, and even online dating can be potential locations for this type of scam. The ultimate goal for bad actors is usually to obtain credit card information, bank account numbers, or other financial information from potential victims. In part one of our overview, we looked at the history, trends, and characteristics of chat application scams. 

In part two, we’ll be covering the most common chat security vulnerabilities, and how you can fix them. We’ll also look at the shortcomings of out-of-the-box security solutions, and some tools PubNub provides that can help you keep your mobile or website application safe from phishing attempts.

Common in-app chat security vulnerabilities

The prevalence of in-app chat functionality in everything from online dating apps to cryptocurrency processors brings along certain security vulnerabilities that developers and architects must be aware of. Here are some of the most common security vulnerabilities in in-app chat and how they can be mitigated.

Problem: Lack of end-to-end encryption

Sometimes, in-app chats may not be end-to-end encrypted, meaning unauthorized individuals can intercept and read the messages. 

Solution: Strong encryption protocols, such as secure communication channels like Transport Layer Security (TLS), are essential to protect user data in transit.

Problem: Inadequate authentication and authorization

Malicious actors may impersonate legitimate users or gain unauthorized access to sensitive information without strong authentication controls. 

Solution: Implementing secure authentication methods, like multi-factor authentication and access control lists, can help mitigate these risks.

Problem: Injection attacks

If proper input validation and sanitization are not in place, it can lead to injection attacks, such as SQL injection or cross-site scripting (XSS). 

Solution: Strict input validation, output encoding, content security policies, and parameterized queries can help prevent these attacks.

Problem: Malware or file-based attacks

Scammers can send infected files or embed malware within innocent-looking files, compromising user devices or the network. 

Solution: Implementing file type validation, scanning files for malware, and restricting file permissions can help mitigate these risks.

Problem: Denial of Service (DoS) attacks

In-app chat functionality can be exploited to launch Denial of Service attacks, where malicious actors overwhelm the system with high requests, causing it to become unresponsive or crash. 

Solution: Implementing rate limiting, session management, and monitoring for unusual traffic patterns can help detect and prevent DoS attacks.

Problem: Privacy concerns

If proper privacy controls are not in place, personal or sensitive information such as phone numbers may be at risk of unauthorized access or exposure. 

Solution: Message encryption, data anonymization, and user consent controls can help protect user privacy.

Problem: Man-in-the-middle (MITM) attacks

When an attacker intercepts the communication between two parties, they can eavesdrop on the conversations, modify the messages, or even impersonate one party. 

Solution: Secure communication protocols like TLS and certificate pinning can help prevent MITM attacks.

Problem: Lack of secure session management

Attackers can exploit vulnerabilities in the session management process to gain unauthorized access to user sessions or manipulate session identifiers. 

Solution: Implementing strong session management practices, such as using unique session identifiers, enforcing session expiration, and employing session encryption, can help mitigate these risks.

Problem: Account takeover attacks

Attackers can exploit vulnerabilities in the authentication process to gain unauthorized access to user accounts, leading to unauthorized activities, data breaches, or even impersonation of legitimate users like the family members of potential victims. 

Solution: Implementing secure authentication mechanisms, such as strong password policies, multi-factor authentication, and account lockouts after multiple failed login attempts, can help prevent account takeover attacks.

Problem: Integration vulnerabilities

In-app chat systems often integrate with third-party services or APIs that can introduce vulnerabilities that attackers can exploit to gain unauthorized access to the chat system or compromise the security of connected systems. 

Solution: Instituting secure authentication and authorization mechanisms, coding practices, conducting regular security assessments of third-party integrations and APIs, and monitoring security vulnerabilities can help mitigate integration risks.

Problem: Social engineering attacks

Attackers manipulate in-app chat users into divulging sensitive information or performing actions compromising security. This can include phishing scams, impersonation, or coercion tactics. 

Solution: Educating potential victims about common social engineering techniques and red flags, implementing multi-factor authentication, and regularly updating security policies can help mitigate the risk of social engineering attacks through the chat system.

Problem: Lack of user awareness and training

Users may inadvertently click on malicious links, share sensitive information, or fall victim to social engineering attacks or identity theft if they are not properly educated about security best practices. 

Solution: Regular security training, awareness about common threats, and user-friendly security measures can help mitigate the risk of human errors and improve overall system security.

Security shortfalls of out-of-the-box chat solutions

In-app chat solution providers each have their strengths and weaknesses, which has pros and cons for app development teams. Out-of-the-box solutions are good options for apps with fewer users and dev teams that prefer plug-and-play options that will get something up and running quickly.

But the problem with these is the lack of advanced features that enable teams to customize their app fully, including implementing features that protect their in-app chat from scammers. Despite attempts for improved security, many in-app chat platforms still lack robust, real-time solutions for scam detection and prevention, giving bad actors an unnerving advantage over unsuspecting users.

Here are some of the common vulnerabilities that plague out-of-the-box in-app chat solutions when it comes to detecting and blocking scams:

  • Lack of advanced fraud detection techniques: Many in-app chat solutions rely on basic keyword filters or manual moderation, which scammers can easily bypass through subtle or disguised language.

  • Ineffective user reporting: If users are not provided with an easy and intuitive way to report suspicious activity, scams may go unnoticed. Additionally, reported content may not be promptly reviewed and actioned upon without a robust moderation system.

  • Inability to analyze context and intent: Traditional chat solutions often struggle to accurately interpret the context and intent behind messages, making it difficult to identify scams that rely on manipulation or coercion tactics.

  • Limited use of artificial intelligence: In-app chat solutions that do not leverage machine learning algorithms or sentiment analysis techniques may miss out on identifying sophisticated scams and patterns of fraudulent behavior.

  • Lack of real-time monitoring: Without real-time monitoring tools, scams may go undetected until after the damage has already been done.

  • Insufficient integration with external data sources: In-app chat solutions that do not integrate with external databases or fraud detection services may miss out on valuable information that could help identify scams.

  • Inadequate user reputation systems: Without a robust system, it can be difficult to identify repeat offenders or users with a history of engaging in scam activities. This can make it easier for scammers to continue their fraudulent behavior undetected.

  • Lack of continuous monitoring and updates: Scammers constantly evolve their techniques and find new ways to exploit vulnerabilities. In-app chat solutions that do not regularly update their detection and blocking mechanisms may become outdated and ineffective in detecting and blocking scams.

  • Limited integration with other security measures: Not integrating with other security measures, such as user authentication or device recognition, may make detecting and blocking scams more difficult. Combining multiple layers of security can significantly increase the chances of detecting and preventing scams.

  • Inadequate training and support for moderators: Moderators play a crucial role in detecting and blocking scams within in-app chat solutions. However, their effectiveness in identifying scams may be compromised if they are not properly trained or provided with the necessary tools and support.

  • Lack of transparency and communication with users: In-app chats that do not communicate their efforts to detect and block scams to their users may result in a lack of trust and confidence in the platform. Transparency and clear communication can help users feel more secure and encourage them to report suspicious activity.

PubNub’s in-app chat security tools

PubNub offers robust chat security thanks to two powerful tools: Functions and Access Manager.

Functions: a powerful tool for scam detection & prevention

Functions provides a powerful serverless compute platform that enables developers to execute custom code in real-time as messages flow through the PubNub network. This functionality can be leveraged to screen chat messages and identify potential scams.

Besides immediate detection, Functions' true strength lies in its power to block potential scams preemptively. Honing in on specific patterns and markers creates a haven for users to engage in scam-free in-app chats.

Functions allows for real-time screening and flagging of suspicious messages, thus disrupting potential scams before they can do any harm. They can be customized extensively to suit your security requirements, making in-app chat environments safer and more trustworthy.

Customizing Functions for scam detection

Functions can be fine-tuned to detect even the most unconventional scams. This paves the way for adaptable security measures that can proficiently keep pace with evolving cyber threats. Functions can hone in on any suspicious dialogue by creating explicit parameters and neural keyword sequences. This gives a pivotal advantage to curtail and thwart increasingly elusive scam attempts.

A hallmark feature of Functions is its ability to gain advanced proficiency in scam detection. This is achieved through steady accumulative learning - as more messages are screened, Functions progressively refines its discernment.

Comprehensive scam detection

Functions can be used to implement a multi-layered approach to scam detection. Companies can create a comprehensive scam detection system by combining rule-based detection using Functions' K/V store with AI-powered detection. Rule-based detection allows for immediate blocking of known scams, while AI-powered detection can identify new and emerging scam patterns. This combination ensures that companies are equipped to detect and block a wide range of scams, providing a safer in-app chat experience for their users.

External API integration

Functions supports external API calls, allowing developers to integrate with any AI service capable of detecting scams and inappropriate content. By leveraging external APIs, companies can enhance their scam detection capabilities and stay up-to-date with the latest scamming techniques.

SMS message delivery

PubNub's Presence feature enables the detection of offline users. When a recipient is offline, companies can use Functions to determine if the message should be sent via SMS instead. This ensures that important messages reach users even when they are not actively using the app

Enforcing SHAFT compliance

Functions can also assist companies in enforcing SHAFT (Sex, Hate, Alcohol, Firearms, or Tobacco) or SHAFT-C (Sex, Hate, Alcohol, Firearms, Tobacco, or Cannabis) rules established by the Cellular Telecommunications Industry Association (CTIA) for SMS messages. 

By publishing all messages into PubNub and using Functions to screen and filter messages, companies can ensure that their SMS messages comply with the CTIA guidelines and that messages are only sent to the SMS gateway if they have appropriate content, reducing costs and ensuring user trust.

Increased efficiency in scam detection and prevention

Functions streamlines scam monitoring by allowing customizable logic deployment directly on data streams. This approach reduces latency and increases efficiency in real-time communication environments.

With PubNub's real-time capabilities (and even some help from OpenAI's ChatGPT integration), developers can intercept, analyze, and manipulate messages as they pass through the network. This immediate action prevents scams from reaching unsuspecting users. Developers can reduce the time spent analyzing messages after arrival, resulting in a swift response time to potential threats.

The Power of PubNub lies in its ability to make real-time detection not just possible but efficient. It empowers applications with a proactive defense mechanism, thereby heightening in-app chat security.

Access Manager: The gatekeeper for safeguarding in-app chat

Another tool in PubNub’s in-app chat security arsenal is the Access Manager. Access Manager provides a comprehensive and flexible security framework that enables fine-grained control over access to chat functionality, ensuring only authorized users can engage in conversations. Here's how it helps protect apps from chat scams:

  1. Authentication and Authorization

  2. Role-Based Access Control (RBAC)

  3. Channel-Level Access Control

  4. Time-Limited Access

  5. Revocation of Access

We’ll get into more detail on each feature below.

Authentication and authorization

PubNub's Access Manager provides a robust framework for managing authentication and authorization within an app's in-app chat system. Here's how Access Manager handles authentication and authorization:


  • Token-Based Authentication: Access Manager allows the app to implement token-based authentication mechanisms such as OAuth, JWT, or custom token authentication. When a user logs in or authenticates with the app, a token is generated and issued. This token serves as proof of identity and is required to access the chat functionality.

  • Token Generation and Management: Access Manager supports token generation and management, enabling the app to generate unique tokens for each user or session. These tokens can be securely stored, managed, and distributed as needed. The tokens are typically signed or encrypted, ensuring their integrity and preventing tampering or spoofing.


  • Role-Based Access Control (RBAC): Access Manager facilitates the implementation of RBAC, allowing the app to assign specific roles or user types with different permissions within the chat system. More details about RBAC are in the following section.

  • Channel-Level Access Control: App developers can define permissions at the channel level, specifying which roles or users can access specific channels. More information is provided about Channel-Level Access Control in a later section.

  • Permission Management: Access Manager provides APIs and tools to manage permissions dynamically. This allows the app to update permissions in real-time based on changing user roles, access requirements, or other dynamic factors. It ensures that users are granted or revoked access to chat functionality as needed, reducing the chances of unauthorized users participating in conversations.

  • Secure Token Handling: Access Manager ensures that tokens used for authentication and authorization are securely handled. Tokens are typically signed, encrypted, or both, to prevent unauthorized tampering or spoofing. This enhances the security of the authentication and authorization process, protecting against fraudulent access attempts.

Role-Based Access Control (RBAC)

PubNub's Role-Based Access Control (RBAC) is crucial for protecting apps from in-app chat scams by providing granular control over user permissions and access within the chat system. Here's how RBAC works:

  • Restricting Unauthorized Actions: RBAC enables the app to define specific roles with different levels of access and permissions. By creating roles such as "user," "moderator," or "administrator," the app can restrict certain actions that may be associated with scam-related activities. For example, users without the "moderator" role might be restricted from sending links or sharing personal information, reducing the risk of scams spreading through the chat system.

  • Limiting Message Content: RBAC allows the app to set permissions on message content based on user roles. This ensures that users without the necessary permissions cannot send messages containing potential scams or prohibited content. By restricting certain roles from engaging in specific chat actions, the app can prevent fraudulent activities and protect users from being targeted by scams or spam.

  • Monitoring User Activity: RBAC enables the app to monitor user activity within the chat system based on their roles. The app can identify potential scammers by tracking actions specific to scam activities, such as suspicious link sharing or repeated attempts to solicit personal information. This monitoring allows for prompt intervention and blocking of fraudulent users or those attempting to engage in suspicious activities.

  • Administering Moderation Features: RBAC empowers the app to designate certain roles with moderation capabilities, allowing them to monitor and moderate chat conversations. Moderators can review messages, flag potential scams, and act appropriately, such as blocking or reporting users who engage in fraudulent activities. This proactive moderation contributes to a safer chat environment by swiftly removing potential scams and protecting users from harm.

  • Dynamic Updates and Flexibility: RBAC allows the app to update user roles and permissions as needed dynamically. If new scam patterns emerge or additional security measures are required, the app can modify roles and permissions to adapt to the evolving threat landscape. This flexibility ensures that the app can respond proactively to emerging scam techniques and stay ahead of potential threats within the chat system.

Channel-Level Access Control

Channel-Level Access Control is another Access Manager feature that helps keep in-app chat secure. Here's how it works to help safeguard against scams:

  • Authorized Channel Access: Access Manager allows the app to specify which users or roles have permission to access specific chat channels. This prevents unauthorized users from joining channels and participating in conversations where scams may exist. By effectively controlling access at the channel level, the app can create a secure and controlled environment for legitimate users.

  • Granular Permission Definitions: With Channel-Level Access Control, the app can define granular permissions for each channel. It can specify the permitted or restricted actions for users within a particular channel. For example, the app can limit certain actions like sending links or sharing personal account information in channels more susceptible to scams. This permissions enforcement helps mitigate the risk of scams being propagated through the chat system.

  • Preventing Unauthorized Channel Creations: Access Manager ensures only authorized users or roles can create new chat channels. This prevents malicious users from creating channels specifically for scam-related activities. By restricting channel creation, the app maintains control over the channels made available to its users, reducing the likelihood of scams occurring within the chat system.

  • Revoking Channel Access: Access Manager enables the app to revoke a user's access to certain channels if suspicious or fraudulent behavior is detected. This immediate action can help contain scams and prevent their further spread. The app can protect users from potential scams by promptly revoking access to affected channels, ensuring a safe chat environment.

  • Dynamic Permission Updates: Access Manager allows for dynamic updates to channel-level permissions. The app can modify channel permissions in real-time if an emerging scam pattern is identified or additional security measures are required. This flexibility empowers the app to respond quickly to evolving scam techniques and adjust access controls accordingly.

Time-Limited Access

Here's how Access Manager safeguards against scams with Time-Limited Access:

  • Limited Access Window: Access Manager allows the app to define time-limited access permissions for users. This means that users are granted access to chat functionality for a specific duration, after which their access expires. By setting a time limit, the app can prevent potential scammers from gaining prolonged access and limit their opportunity to engage in fraudulent activities.

  • Temporary Channel Access: Access Manager enables the app to grant time-limited access to specific chat channels or rooms. Users are only allowed to join and participate in conversations within these channels for a defined period. Once the time limit expires, their access to the channels is automatically revoked. This prevents scammers from infiltrating channels for an extended period and mitigates the risk of scams spreading within the chat system.

  • Dynamic Time Limit Updates: Access Manager allows dynamic updates to time limits for user access. This is particularly useful when scams or fraudulent activities are detected, as the app can quickly reduce the time limit for users suspected of engaging in suspicious behavior. By shortening the access window, the app can mitigate the impact of scams and limit their potential damage.

  • Prevention of Persistent Scammers: Time-Limited Access helps prevent persistent scammers from continuously exploiting the chat system. With access expiring after a specific duration, scammers are unable to maintain a long-term presence within the chat environment. This reduces their ability to target multiple users, decreasing the overall risk of scams occurring within the system.

  • Continuous Access Renewal: Access Manager allows the app to renew a user's access for a specific channel or the chat system by extending their time-limited access if necessary. This flexibility ensures that legitimate users can continue participating in conversations without interruption while maintaining the time-limited protection against potential scammers. Access renewal can be transparent to users, enhancing their experience while safeguarding against scams.

Revocation of Access

PubNub's Access Manager ensures the security of in-app chat systems by utilizing the powerful Revocation of Access feature. Here's how in-app chats are kept secure from scams with this feature:

  • Prompt Detection and Response: Access Manager allows the app to monitor user behavior and detect suspicious activities in real-time. When fraudulent or scam-related behavior is identified, the app can promptly revoke the user's access to the chat system. This immediate action prevents scammers from continuing their fraudulent activities and limits their impact on the chat environment.

  • Containing Scams: Revocation of Access enables the app to swiftly contain scams within the chat system. By revoking the access of users engaged in scam activities, the app prevents the spread of scams to other users. It helps maintain a safe environment for legitimate users and reduces the risk of scams affecting a wider audience.

  • Minimizing User Exposure: Access Manager's Revocation of Access feature ensures that users are protected from potential scams by promptly revoking access for suspicious users. This reduces the likelihood of users falling victim to fraudulent activities and minimizes their exposure to harmful content or scam attempts within the chat system.

  • Prevention of Repeated Offenses: With Revocation of Access, the app can prevent scammers from repeatedly accessing or rejoining the chat system. When a user's access is revoked due to fraudulent behavior, it becomes more challenging for them to re-engage in scam activities within the app. This feature helps discourage scammers from persistently targeting the chat environment.

  • Proactive Scam Prevention: By utilizing the Revocation of Access feature, the app can take proactive measures to prevent scams and protect users. With continuous monitoring and immediate revocation of access upon detecting scam-related activities, Access Manager ensures a secure chat environment and helps maintain trust among users.

With these two powerful tools, PubNub enables developers to secure their in-app chat in ways that other solutions can’t match.


PubNub's in-app chat solution offers a powerful and efficient way for companies to detect and block scams and inappropriate user behaviors. By leveraging Functions and its serverless compute platform, companies can implement real-time scam detection, adapt quickly to new scamming techniques, and scale their detection capabilities as their user base grows. 

Integrating AI services further enhances scam detection by leveraging advanced machine learning algorithms and staying up-to-date with the latest scamming techniques. With PubNub's comprehensive scam detection approach and compliance with SHAFT rules, companies can provide their users with a safer in-app chat experience while saving time and reducing infrastructure setup and maintenance costs.

Let PubNub help you protect your organization from the damage caused by scammers targeting in-app chat users. Contact us today to discuss your project, or sign up for a free trial to get up to 200 MAUs or 1M monthly transactions for free.