What are the best practices for handling a list bombing attack and account compromise?

Summary

In the event of a list bombing attack and potential account compromise, a multi-faceted approach is crucial. It begins with understanding the scope of the breach and identifying affected accounts, especially high-value ones like banking and email. Immediate actions include carefully monitoring financial accounts for suspicious activity, contacting your ESP to mitigate malicious subscriptions, and setting up fraud alerts with credit bureaus. Enhancing account security by changing passwords (except during the height of the attack), enabling two-factor authentication, and using password managers is vital. Being vigilant for phishing attempts and regularly reviewing app permissions are also key. Long-term protection involves opting out of data broker sites and adjusting privacy settings. It's important to remember the attack will likely subside in 48 hours. Further, know to report incidents to authorities like the FTC and consider identity protection services for ongoing security.

Key findings

  • Scope and Target: List bombing often masks another attack. Be aware that you might be targeted to distract you from other events, such as an attempted account takeover.
  • Phishing: High-value accounts are the likely target. Always be on the lookout for phishing attempts on financial, social media and email accounts.
  • Initial Actions: Contact your ESP to purge bad subscriptions. Monitor accounts.
  • Password Management: Change compromised passwords after the initial attack, use a password manager, and enable 2FA.
  • Financial Safety: Set up fraud alerts with credit bureaus and monitor for suspicious activity on financial accounts. Consider a credit freeze.
  • Long-term Strategy: Opt out of data brokers, review privacy settings, and consider identity protection services.
  • Attack Duration: Expect most of the attack volume to subside within 48 hours.
  • Deliverability Impact: List bombing can significantly impact deliverability as mailbox providers throttle or block the email account.

Key considerations

  • Distraction factor: Assume the list bombing is designed to distract you from other events that are occurring, so be extra vigilant.
  • Reporting the crime: Report any evidence of a crime to the authorities, especially if money was lost. Do this early so it's not forgotten later.
  • Password resets: Never reset your password during an ongoing attack. Wait until it subsides and ensure the computer is free of malware, then use a password manager with two-factor authentication to make changes.
  • Account Organization: Use groups or aliases to help sort the accounts and filter by sender.
  • Think long-term: Take proactive steps to reduce exposure, such as opting out of data broker sites. Use a password manager
  • Third-party Permissions: Check the permissions of third-party apps connected to your social media and email accounts, and revoke them as needed.
  • Leverage Support: Contact fraud support teams to ensure that all is being handled correctly.

What email marketers say
22Marketer opinions

In the event of a list bombing attack and potential account compromise, the primary focus should be on securing sensitive accounts and preventing further unauthorized access. Immediate actions include identifying the scope of the breach, changing passwords (except during the initial attack phase), enabling two-factor authentication, and monitoring financial accounts for suspicious activity. It is recommended to contact ESPs to purge malicious subscriptions, consider using a password manager with unique passwords, and be wary of phishing attempts. Additionally, measures such as placing credit freezes, opting out of data brokers, and adjusting privacy settings can help mitigate long-term risks.

Key opinions

  • Scope of Breach: Identify affected accounts, prioritizing high-value ones like banking and email.
  • Password Security: Change passwords (after the initial attack), use a password manager for unique, strong passwords. Avoid resetting passwords during the initial flooding.
  • Two-Factor Authentication: Enable 2FA on all possible accounts for an extra layer of security.
  • Financial Monitoring: Closely monitor financial accounts and credit reports for unauthorized activity; set up fraud alerts and consider a credit freeze.
  • Phishing Awareness: Be cautious of phishing attempts, as attackers may leverage compromised information.
  • Contacting ESPs: Reach out to ESPs to purge malicious subscriptions and mitigate the list bombing.

Key considerations

  • Timing of Password Changes: Avoid changing passwords during the initial list bombing phase to prevent potential lockouts due to malicious password reset attempts.
  • Long-Term Protection: Consider using tagged email aliases and adjust privacy settings to limit future exposure.
  • Reporting Incidents: Report incidents of fraud or identity theft to relevant authorities like the FTC.
  • Proactive Measures: Opt-out of data broker sites and regularly review app permissions to minimize personal data exposure.
  • Credit Union support: Leverage fraud support from banks or credit unions as a primary course of action.
  • Account monitoring: Use services like “Have I been pwned” to monitor for potential breaches.
Marketer view

Marketer from Email Geeks shares to reach out to the various ESPs, explain you are being added malicious to accounts/lists and ask for a purge from subscriptions for the last X timeframe.

June 2023 - Email Geeks
Marketer view

Email marketer from Reddit explains to report the incident to relevant authorities, such as the FTC or local law enforcement, especially if identity theft or financial fraud has occurred.

July 2021 - Reddit
Marketer view

Marketer from Email Geeks advises against resetting passwords unnecessarily in the middle of a potential attack which will likely include password reset confirmation type messages.

September 2023 - Email Geeks
Marketer view

Marketer from Email Geeks shares that the attack won't last forever (fortunately): the attackers are paying for a service to bomb you, and this service costs them money. So this is not an endless tunnel.

August 2024 - Email Geeks
Marketer view

Email marketer from Have I Been Pwned recommends using the Have I Been Pwned website to check if your email address or phone number has been involved in any known data breaches.

January 2024 - Have I Been Pwned
Marketer view

Marketer from Email Geeks suggests working with your bank’s identity protection services or a 3rd party to find the best long term solution to protect you from liability.

July 2021 - Email Geeks
Marketer view

Marketer from Email Geeks suggests that list bombing often happens in order to mask something else, so check for mail from your bank or other providers for notifications that your login or other details have been updated.

May 2021 - Email Geeks
Marketer view

Marketer from Email Geeks suggests spreading things out using various groups for siloed apps, i.e. banking@ is for bank, etc. or use tagged aliases, you use gmail. So you can could something like <mailto:francisbaker+BRANDHERE@gmail.com|francisbaker+BRANDHERE@gmail.com>. This way if it happens again they _might_ spam that alias so you could filter that specifically away.

March 2021 - Email Geeks
Marketer view

Email marketer from Lifehacker shares that enabling two-factor authentication (2FA) on all accounts that offer it adds an extra layer of security, making it more difficult for attackers to gain access even if they have your password.

February 2025 - Lifehacker
Marketer view

Marketer from Email Geeks suggests that if you enable tabs on your gmail to include updates and promotions it might be easier to scroll and scan what's important. All of my banking and really important stuff ends up in updates or inbox. so once you do the keyword searches as <@U2UGZ5V33> said then after you can do a more manual search. It will also be easier when you want to delete all this crap you can just delete all the stuff in your promotions tab.

May 2022 - Email Geeks
Marketer view

Marketer from Email Geeks suggests changing the password of your email account, and look for emails from your bank or other money-related accounts you may have.

November 2022 - Email Geeks
Marketer view

Marketer from Email Geeks advises not to call any phone numbers in the message that told you about the charge and to instead look up the number from their website.

February 2022 - Email Geeks
Marketer view

Marketer from Email Geeks explains that the user has been a target of list bombing and should keep a close eye on personal accounts as this is a common tactic to flood inbox while they try to take over an account.

February 2025 - Email Geeks
Marketer view

Email marketer from Experian shares that setting up fraud alerts with credit bureaus, this requires creditors to take steps to verify your identity before issuing credit in your name.

August 2024 - Experian
Marketer view

Email marketer from Privacy Rights Clearinghouse explains that reviewing the privacy settings on your online accounts and adjusting them to be more restrictive can help limit the amount of personal information available to potential attackers.

September 2024 - Privacy Rights Clearinghouse
Marketer view

Marketer from Email Geeks shares that if you are under attack, the objective is going to be to con you into doing something, most likely authenticating yourself to (what looks like) a financial institution or provider you use. That will allow them to steal from you. They will use your adrenaline against you as that can short circuit critical thinking. Best advice is don't make any changes to anything for next 24 hours.

November 2021 - Email Geeks
Marketer view

Marketer from Email Geeks shares that it may not be malicious, in that, you may not be the target. If you are the target the idea is to flood your mailbox with clutter so you don't notice the "Your account credentials have been changed" type message from your bank.

June 2023 - Email Geeks
Marketer view

Email marketer from Troy Hunt's Blog shares that the initial step is to understand the scope of the breach by identifying which accounts used the compromised password. He further recommends focusing on high-value accounts first, such as banking and email accounts.

March 2023 - Troy Hunt's Blog
Marketer view

Email marketer from Consumer Reports suggests opting out of data broker sites, which collect and sell your personal information, to reduce your online exposure.

October 2022 - Consumer Reports
Marketer view

Email marketer from Krebs on Security recommends placing a credit freeze with all three major credit bureaus (Equifax, Experian, TransUnion) to prevent unauthorized accounts from being opened in your name.

August 2023 - Krebs on Security
Marketer view

Email marketer from Norton advises being extra cautious of phishing attempts, as attackers may use the compromised information to craft more convincing scams.

January 2025 - Norton
Marketer view

Email marketer from Reddit explains the user should use a password manager with unique, randomly generated passwords for each account to mitigate the risk of password reuse.

May 2024 - Reddit

What the experts say
7Expert opinions

In the event of a list bombing attack, immediate steps should be taken to mitigate the damage. It's crucial to monitor emails closely, especially those related to password resets or sensitive accounts, and to update security measures like passwords and two-factor authentication. Creating inbox rules to filter out subscription confirmation emails can help manage the volume. Contacting your ESP is important to help mitigate the attack. Although the bulk of the attack might subside within a couple of days, list bombing can negatively impact email deliverability by causing throttling or blocking by mailbox providers.

Key opinions

  • Attack Duration: The main volume of a list bombing attack usually subsides within 48 hours.
  • Email Monitoring: Closely monitor emails for password reset requests and suspicious activity on sensitive accounts.
  • Security Updates: Update email passwords, enable two-factor authentication, and run malware scans.
  • Inbox Rules: Create inbox rules to filter out subscription confirmation emails.
  • ESP Contact: Contact your Email Service Provider (ESP) for assistance in mitigating the attack.
  • Deliverability Impact: List bombing can lead to throttling or blocking by mailbox providers, affecting email deliverability.

Key considerations

  • Proactive Filtering: Set up rules to automatically delete subscription confirmation emails to reduce clutter.
  • Kickbox integration: Implement measures to mark the compromised email address as undeliverable for new sign-ups.
  • Ongoing Monitoring: Continue to monitor accounts even after the initial attack subsides.
Expert view

Expert from Email Geeks shares to keep an extra close eye on emails trying to reset passwords, or access sensitive accounts like banking or other financial, along with your social accounts. possibly run a search of your inbox for terms like password reset, successful login, or other terms like this.

April 2023 - Email Geeks
Expert view

Expert from Email Geeks explains that there isn’t much you can do. One of their addresses got bombed a few years ago (targeted harassment) and most of the volume passed in 48 hours or so.

August 2024 - Email Geeks
Expert view

Expert from Word to the Wise advises contacting your Email Service Provider (ESP) immediately during a list bombing attack to inform them of the situation. ESPs can assist in identifying and mitigating the flood of subscriptions or messages.

March 2022 - Word to the Wise
Expert view

Expert from Email Geeks shares they set Anne's Gmail address as “undeliverable” in the Kickbox email verification platform so anybody that uses them to verify addresses at signup will get told to reject yours and set it to expire in 10 days.

January 2022 - Email Geeks
Expert view

Expert from Spam Resource explains that list bombing can significantly impact deliverability as mailbox providers may throttle or block emails due to the sudden surge in volume. This action prevents future emails reaching your inbox.

October 2023 - Spam Resource
Expert view

Expert from Email Geeks suggest to create a rule in your inbox to delete emails with the words "Confirm your subscription", "welcome to". and other repeating phrases from these incoming messages, to have a few less things to look at.

February 2024 - Email Geeks
Expert view

Expert from Email Geeks advises to change your email password and add 2 factor authentication, sign-out all remote sessions and run malware scans on your PC to ensure it's clean; also to get a password manager and use long and unique password everywhere.

July 2023 - Email Geeks

What the documentation says
4Technical articles

Following an account compromise, security documentation emphasizes immediate and thorough action. It's crucial to change passwords for all affected accounts, prioritizing those with shared passwords, and to enable multi-factor authentication for enhanced security. Continuous monitoring of financial accounts, credit reports, and credit card statements is essential to detect and report any unauthorized activity. Running a full system scan with anti-malware software can help remove any malicious software. Reviewing and revoking permissions granted to third-party apps connected to email and social media accounts reduces the risk of unauthorized access.

Key findings

  • Password Changes: Change passwords for all affected accounts, particularly those with shared passwords.
  • Multi-Factor Authentication: Enable multi-factor authentication (MFA) on all accounts where available.
  • Financial Monitoring: Monitor financial accounts, credit reports, and credit card statements for unauthorized activity and report any suspicious transactions immediately.
  • System Scan: Run a full system scan with reputable anti-malware software to detect and remove any malicious software.
  • App Permissions: Review permissions granted to third-party apps connected to email and social media accounts and revoke access for any apps no longer used or not recognized.

Key considerations

  • Timeliness: Take these steps immediately upon detecting a compromise.
  • Thoroughness: Ensure all affected accounts are addressed, and permissions are thoroughly reviewed.
  • Reporting: Report any suspicious transactions or signs of identity theft to the relevant authorities.
Technical article

Documentation from Federal Trade Commission advises to closely monitor bank accounts, credit card statements, and credit reports for any unauthorized activity and to report any suspicious transactions immediately.

March 2022 - Federal Trade Commission
Technical article

Documentation from CISA (Cybersecurity and Infrastructure Security Agency) recommends running a full system scan with reputable anti-malware software to detect and remove any malicious software that may have been installed during the compromise.

March 2021 - CISA
Technical article

Documentation from Microsoft shares reviewing the permissions granted to third-party apps connected to your email and social media accounts, and revoking access for any apps you no longer use or don't recognize.

October 2022 - Microsoft
Technical article

Documentation from NIST.gov advises that after detecting a compromise, immediately change passwords for all affected accounts, especially those with shared passwords. Enable multi-factor authentication wherever possible.

May 2021 - NIST.gov