DroneBL is a real-time blocklist that lists IP addresses of compromised systems, often referred to as 'drones.' It focuses on various security threats such as open proxies, botnets, and systems involved in brute-force attacks, rather than solely spamming activity.

How long does it take to get delisted from DroneBL?

The time it takes to get delisted from DroneBL can vary, but it is generally a quick process once the underlying issue (e.g., compromised system, open proxy) is resolved and a delisting request is submitted through their website. Timely action is key.

Does DroneBL affect email deliverability?

While DroneBL primarily focuses on network security issues rather than email spam, a listing can indirectly affect your email deliverability. It contributes to a negative IP reputation and might cause some mail servers or security platforms to flag or block your emails. Its impact is generally less direct than major spam-focused blocklists.

What are common reasons for a DroneBL listing?

Common reasons include your IP acting as an open proxy (SOCKS, HTTP, Wingate), being part of a botnet or DDoS attack, or engaging in brute-force attacks on honeypots. It also lists compromised routers, IRC drones, and systems infected with auto-rooting worms. The root cause is often a security vulnerability or misconfiguration on your network.

How can I check if my IP is listed on DroneBL?

You can check if your IP address is listed on DroneBL by visiting their official website and using their IP lookup tool. The tool will show your current IP and any active listings, along with the specific reason for the listing.

Why is my IP listed on DroneBL and how to remove it? - Troubleshooting - Email deliverability - Knowledge base

Discovering that your IP address is listed on a blocklist can be an immediate cause for alarm. When my cybersecurity team recently informed me that a couple of our sending IPs were listed on DroneBL, the immediate reaction was understandable panic and demands for swift removal.

DroneBL is a real-time blocklist (also referred to as a blacklist) that focuses on IP addresses identified as compromised systems, known as 'drones.' Unlike many blocklists primarily concerned with spam, DroneBL casts a wider net, targeting various security threats like open proxies, botnets, and systems involved in brute-force attacks. This distinction is crucial, as a listing here might not directly impact your email deliverability as severely as a major spam-focused blocklist, but it certainly signals a potential security vulnerability within your network.

Understanding why your IP landed on DroneBL and the proper steps to take for its removal is essential. While the direct email deliverability impact might be secondary, the presence of your IP on such a list can still affect your overall network reputation and be a red flag for security audits.

Why your IP is listed on DroneBL

DroneBL classifies listed IP addresses into various categories, indicating the specific type of malicious activity detected. While some categories, like "Unknown spambot or drone," might suggest email-related abuse, many point to broader network compromises. For instance, an IP could be listed for being an "Open SOCKS Proxy" or an "Open HTTP Proxy," indicating that your system might be inadvertently used by attackers for relaying traffic.

A common reason for an IP to be listed on this blocklist (or blacklist) is involvement in "Brute force attackers," often accompanied by a note about "dictionary attack on honeypots." This means your system might have attempted to log into a honeypot system, indicating either a compromised machine or a misconfigured application trying to reach invalid addresses repeatedly. If your organization maintains email lists, sending to outdated or unvalidated contacts can inadvertently lead to hitting spam traps that behave like honeypots, even if the primary intention wasn't a malicious attack.

It's important to differentiate between a general email blocklist and one focused on system compromise. A listing on DroneBL (or any similar blacklist) suggests a deeper security issue that goes beyond just email sending practices. Other common reasons include IPs acting as "DDOS Drones" or being part of a "ProxyChain" network, which are direct indications of system misuse rather than just spamming activity.

Code	Description
3	IRC Drone: IP associated with malicious IRC activity.
6	Unknown spambot or drone: Generic malicious activity detected.
8	SOCKS Proxy: IP acting as an open SOCKS proxy.
13	Brute force attackers: Involved in dictionary attacks on honeypots.
15	Compromised router / gateway: Network device has been breached.

How a DroneBL listing affects you

The impact of a DroneBL listing can vary. For email marketers, the direct effect on inbox placement might not be as pronounced as a listing on a major spam blocklist like Spamhaus. However, it still contributes to a negative IP reputation and could indirectly affect how mail servers view your sending IP over time.

Where DroneBL listings truly hurt is in broader network security assessments. Many organizations use security rating services like Security Scorecard, which aggregate data from various sources to provide a score reflecting an entity's security posture. A DroneBL listing can negatively impact this score, potentially affecting business relationships, insurance premiums, or even compliance checks.

Even if your email deliverability isn't immediately shattered, a listing on any IP blacklist signals a vulnerability that needs to be addressed. It means a part of your network might be compromised or misconfigured, making it a target for malicious activity. This is why cybersecurity teams often react strongly to such listings, prioritizing their removal regardless of direct email impact.

Email deliverability impact

While not a primary email blocklist, it can contribute to a lower sender reputation over time, indirectly affecting inbox placement. Its impact is less severe than CBL or Spamhaus XBL.

Security score impact

DroneBL listings are often used by security assessment platforms, potentially leading to a reduced security score for your organization, which can impact contracts and partnerships.

Investigating and resolving the listing

The first step in resolving a DroneBL listing is to identify the exact nature of the problem. DroneBL provides a lookup tool on their website where you can enter your IP address to see if it's listed and, more importantly, the reason for the listing. This will give you a clear indication of whether it's an open proxy, a dictionary attack, or another type of drone activity.

DroneBL lookup example

https://dronebl.org/lookup
Your IP Address: 205.139.105.170
Listed Reason: Brute force attackers (dictionary attack on honeypots)

Once you know the reason, you must address the root cause of the listing. If it's an open proxy, you need to secure your systems to prevent unauthorized access. If it's related to dictionary attacks, investigate the software or scripts on your servers that might be attempting connections to invalid destinations, and review your email list hygiene to ensure you're not hitting spam traps. This corrective action is paramount; without it, your IP will likely be re-listed even if removed.

Address the root cause

Delisting requests are effective only if the underlying issue has been resolved. Ensure any vulnerabilities, such as open proxies or compromised systems, are patched and secured before proceeding with the removal request. Ignoring the root cause will lead to re-listing.

After addressing the root cause, you can request delisting. DroneBL is generally cooperative and offers a straightforward delisting process directly through their website's FAQ. Usually, once you input your IP and click the delist button, the process begins, and if the issue is resolved, your IP should be removed fairly quickly. Always monitor your IP address on blocklists proactively to catch and address problems early.

Preventing future DroneBL blocklistings

The best way to avoid future DroneBL listings, and indeed any IP blocklist, is to implement robust security practices across your network. This includes regularly auditing your servers, ensuring all software is up-to-date, and patching known vulnerabilities. Proactive security measures can prevent your systems from being compromised and subsequently listed for malicious activities.

For email sending, particularly if you manage smaller client lists that might have varying levels of hygiene, strict list validation is key. Regularly clean your email lists to remove inactive users, bounce addresses, and known spam traps. This not only improves your overall deliverability but also minimizes the risk of hitting honeypots that could lead to blocklistings (or blacklistings) like those on DroneBL.

Finally, continuous monitoring of your IP reputation across various blocklists, including DroneBL, is a crucial preventative measure. Early detection allows for prompt action, minimizing the impact of any listing. By being proactive, you can maintain a clean IP reputation and ensure your legitimate communications reach their intended recipients without unnecessary interruptions.

Views from the trenches

Best practices

Implement robust security measures for all servers to prevent compromises and open proxies.

Regularly audit your network for vulnerabilities that could lead to DroneBL listings.

Maintain strict email list hygiene to avoid hitting honeypots and spam traps.

Proactively monitor your IP addresses across various security and email blocklists.

Common pitfalls

Ignoring DroneBL listings because they are not primarily email blocklists.

Failing to address the underlying security vulnerability before requesting delisting.

Not understanding the difference between security-focused blocklists and spam-focused ones.

Having unmanaged or 'loosey-goosey' sending practices, especially with smaller client lists.

Expert tips

DroneBL primarily lists compromised machines, making it a valid concern for security teams.

Delisting from DroneBL is typically straightforward once the root cause is fixed.

The impact on email deliverability from a DroneBL listing is usually indirect.

Security Scorecard might not directly use DroneBL data, but the underlying issue still needs addressing.

Expert view

Expert from Email Geeks says a listing in DroneBL is not always related to spam, but often to open proxies or security problems, primarily compromised machines.

2022-09-15 - Email Geeks

Marketer view

Marketer from Email Geeks says their security team is concerned because this listing impacts their Security Scorecard and potential contracts, despite its direct impact on email deliverability being less clear to them.

2022-09-16 - Email Geeks

Maintaining a clean IP reputation

Dealing with a DroneBL listing, or any IP blocklist for that matter, requires a clear understanding of its purpose and impact. While it might not always directly halt your email campaigns, it invariably signals a deeper security issue that needs immediate attention.

Proactive security measures, thorough investigation of the root cause, and prompt delisting requests are essential. By integrating diligent security practices with effective email list management, you can minimize your risk of landing on blocklists like DroneBL and ensure a healthier, more trustworthy online presence for your organization.