Dropbox is reporting a recent “security incident” in which an attacker gained unauthorized access to the Dropbox Sign (formerly HelloSign) production environment. During this access, the attacker had access to Dropbox Sign customer information.

Dropbox Sign is a platform that allows customers to digitally sign, edit, and track documents. The accessed customer information includes email addresses, usernames, phone numbers, and hashed passwords, in addition to general account settings and certain authentication information such as API keys, OAuth tokens, and multi-factor authentication. The access is limited to Dropbox Sign customers and does not affect users of other Dropbox services because the environments are largely separate.

“We believe that this incident was isolated to Dropbox Sign infrastructure and did not impact any other Dropbox products.”

Even if you never created a Dropbox Sign account but received or signed a document through Dropbox Sign, your email addresses and names were exposed. In a government (K-8) filing about the incident, Dropbox says it found no evidence of unauthorized access to the contents of customers’ accounts (i.e. their documents or agreements), or their payment information. 

The attacker compromised a back-end service account that acted as an automated system configuration tool for the Dropbox Sign environment. The attacker used the privileges of the service account for the production environment to gain access to the customer database.

To limit the aftermath of the incident, Dropbox’s security team reset users’ passwords, logged users out of any devices they had connected to Dropbox Sign, and is coordinating the rotation of all API keys and OAuth tokens.

For customers with API access to Dropbox Sign, the company said new API keys will need to be generated and warned that certain functionality will be restricted while they deal with the breach.

Dropbox says it has reported this event to data protection regulators and law enforcement.

Recommendations

Dropbox expired affected passwords and logged users out of any devices they had connected to Dropbox Sign for further protection. The next time these users log in to their Sign account, they’ll be sent an email to reset the password. Dropbox recommends users do this as soon as possible.

If you’re an API customer, to ensure the security of your account, you’ll need to rotate your API key by generating a new one, configuring it with your application, and deleting your current one. Here is how you can easily create a new key.

API customers should be aware that names and email addresses for those who received or signed a document through Dropbox Sign, even if they never created an account, were exposed. So, this may impact their customers.

Customers who use an authenticator app for multi-factor authentication should reset it. Please delete your existing entry and then reset it. If you use SMS you do not need to take any action.

If you reused your Dropbox Sign password on any other services, we strongly recommend that you change your password on those accounts and use multi-factor authentication when available.

Protecting yourself from a data breach

There are some actions you can take if you are, or suspect you may have been, the victim of a data breach.

• Check the vendor’s advice. Every breach is different, so check with the vendor to find out what’s happened and follow any specific advice they offer.
• Change your password. You can make a stolen password useless to thieves by changing it. Choose a strong password that you don’t use for anything else. Better yet, let a password manager choose one for you.
• Enable two-factor authentication (2FA). If you can, use a FIDO2-compliant hardware key, laptop, or phone as your second factor. Some forms of two-factor authentication (2FA) can be phished just as easily as a password. 2FA that relies on a FIDO2 device can’t be phished.
• Watch out for fake vendors. The thieves may contact you posing as the vendor. Check the vendor website to see if they are contacting victims and verify any contacts using a different communication channel.
• Take your time. Phishing attacks often impersonate people or brands you know, and use themes that require urgent attention, such as missed deliveries, account suspensions, and security alerts.
• Set up identity monitoring. Identity monitoring alerts you if your personal information is found being traded illegally online, and helps you recover after.

Check your digital footprint

Malwarebytes has a new free tool for you to check how much of your personal data has been exposed online. Submit your email address (it’s best to give the one you most frequently use) to our free Digital Footprint scan and we’ll give you a report and recommendations.

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Cloud storage and file sharing company Dropbox disclosed a security breach that resulted in an unauthorized access to sensitive information, including passwords and other authentication information. Dropbox revealed that the breach targeted its production environment, specifically impacting Dropbox Sign, formerly known as HelloSign, a platform for digitally signing documents, in an 8-K filing with the U.S. Securities and Exchange Commission.

"The actor compromised a service account that was part of Sign’s back-end, which is a type of non-human account used to execute applications and run automated services. As such, this account had privileges to take a variety of actions within Sign’s production environment. The threat actor then used this access to the production environment to access our customer database.

The accessed information pertains to all Dropbox Sign users, encompassing account settings, names and emails. For some users, additional data such as phone numbers, hashed passwords and authentication information like API keys, OAuth tokens and multi-factor authentication were also compromised.

"From a technical perspective, Dropbox Sign’s infrastructure is largely separate from other Dropbox services. That said, we thoroughly investigated this risk and believe that this incident was isolated to Dropbox Sign infrastructure, and did not impact any other Dropbox products."

While forensic investigators are engaged and law enforcement notified, regulatory agencies are being informed based on the presumption of personal information access. Dropbox has initiated steps to mitigate the impact of the breach, including rotation of OAuth tokens and generating new API keys for customers with API access to Dropbox Sign. Certain functionalities will remain restricted until API keys are rotated, Dropbox said. User notifications are underway, with Dropbox reaching out to affected users and providing guidance on necessary actions. The company expects all notifications to be completed within the next week. Although Dropbox does not anticipate a significant impact on its operations or financial condition, it acknowledges potential risks, including litigation, changes in customer behavior and heightened regulatory scrutiny. This Dropbox data breach incident marks another security challenge for the file sharing giant, following a phishing campaign in 2022 that targeted its developers, resulting in unauthorized access to company GitHub accounts and sensitive information. Media Disclaimer: This report is based on internal and external research obtained through various means. The information provided is for reference purposes only, and users bear full responsibility for their reliance on it. The Cyber Express assumes no liability for the accuracy or consequences of using this information.