Ever wonder why so much spam exists today? By some estimates, more than 100 billion spam messages are sent every day. This represents around 85 percent of global daily email traffic. Some of the most common types of spam messages include financial scams, phishing attempts, ransomware, and botnet malware. In this article, we focus primarily on botnets.
Spam is big business. The barriers to entry are low and the payoffs are high. If a spammer sends out 50,000 spam messages, but only a handful of users click on a link in one of these messages, the spammer’s efforts will likely have paid off.
A single spammer may not have the resources to send out a large-scale spam attack, however, a spammer’s job is made much easier by the use of botnets – networks of hundreds or even thousands of malware-infected computers (known as spambots) that can be remotely controlled over the internet. Similar to legitimate cloud services such as Amazon’s AWS, a botnet-for-hire provides individuals with ample cloud-based resources to carry out large-scale spam campaigns with very little effort.
According to Spamhaus, the top five countries with the most spambots are India, Vietnam, China, Iran, and Brazil. As of May 23, 2016, India had close to 2 million spambots!
The botnet-for-hire industry is a growing industry that makes it easy for anyone to send out thousands of spam messages using the botnet as the attack vector.
In addition to sending out spam, botnets can be used to launch DDoS attacks by flooding a company with thousands of connections over a short period of time – in an effort to try to shut down a company’s network or to damage its reputation.
User education is likely the most important factor in preventing a computer from becoming a spambot. The following are a few guidelines that every email user should know by now.
Never open an email from an unknown source.
Never open an attachment from an unknown source.
Even if the sender appears to be someone you know, always verify – because spammers often forge the sender’s address.
Use anti-virus software on your local computer.
Learn how to recognize phishing
Messages that contain threats to shut your account down
Requests for personal information such as passwords or Social Security numbers
Words like “Urgent” – portraying a false sense of urgency
Forged email addresses
Poor writing or bad grammar
Don’t give your email address to sites you don’t trust.
Don’t post your email address to public websites or forums.
Understand that reputable businesses will never ask for personal information via email.
The information provided above applies primarily to end users, but what actions can be taken by the mail server administrator to detect and prevent spambot activity? While MDaemon has many spam-fighting features, MDaemon 16 includes tools to detect spambot activity and block it from further communication with your server. This new feature is called Spambot Detection. Spambot Detection tracks the IP addresses that every return-path value (sender) uses over a period of time. If the same return-path is used by multiple IP addresses (more than can be expected from users switching between their computers and mobile devices) in a given timeframe, then it’s possible that this activity is being generated by a spambot. Of course, it’s also possible that this activity is completely legitimate. However, in some cases, tests have shown that this can be an effective tool at detecting a distributed spambot network as long as the same return-path is used in the spam messages. If a spambot is detected the connection is dropped and the return-path value is optionally blacklisted for a designated period of time. You can also optionally blacklist all known spambot IPs for a designated period of time.
As with most MDaemon security features, various settings allow you to bypass Spambot Detection for mail from trusted sources. You can exempt specific IPs, senders, and recipients from Spambot Detection using the White list feature, and exempt connections from authenticated sessions or trusted IPs. Click on the Advanced buttons to view a list of return-paths or IPs that are currently blocked. If a return-path or IP is blocked by mistake, you can easily remove it from the list.
We demonstrate how to configure Spambot Detection in this tutorial video.
Spammers are always coming up with new ways to spam users. That’s why user education and a properly configured mail server are equally important in the war against spam.
If you haven’t seen our YouTube channel lately, you’re missing out on some valuable information that can be used to help you manage MDaemon and SecurityGateway. Recently, we’ve added several new MDaemon tutorial videos. Here are a few that might interest you.
MDaemon Graphical User Interface (GUI) Overview
In this video, we provide a tour of MDaemon’s graphical user interface. We show you where to find key security, administration, and account management settings, how to navigate your way through the mail queues, and how to find information in the mail routing, security and spam filter logs using the tabs across the bottom of the MDaemon interface.
MDaemon’s File Structure
One of the benefits of MDaemon that make it easy to troubleshoot and administer is its file structure. All key settings are stored in configuration files located in the MDaemon/App directory, and user email messages are stored in the Users directory. This flat-file structure makes MDaemon very easy to backup and restore using simple drag & drop.
How to Enable and Use Two-Factor Authentication in WorldClient
Two-factor authentication is a security feature found in WorldClient, MDaemon’s webmail client, which requires users to submit two forms of identifying data – a password, and a special code or token, before they are able to login. Two-factor authentication helps prevent accounts from being hijacked by someone who manages to guess the account’s password. A potential hacker would have to know the second authenticating factor in order to access the account.
Enabling Do Not Disturb to Establish Work/Life Balance for Employees
MDaemon’s Do-Not-Disturb feature allows administrators to set a time during which certain users are not allowed to check for or send new email messages. In an age where we’re all constantly connected via mobile devices, this helps foster better work-life balance for your users.
MDaemon 16.0.2 has been released. This update includes a “remember me” feature for two-factor authentication in WorldClient. With this feature enabled, users will not have to re-enter a verification code for a designated period of time.
Other new features and enhancements include:
Global administrators can now set the Mail Archive path in Remote Administration.
The Remote Administration group editor now supports Do Not Disturb scheduling. This allows administrators to schedule a period of time during which email cannot be accessed for all accounts that have been assigned to a group.
Administrators can now sort the Active Sessions list in Remote Administration – for an improved view of server activity.
Global administrators can now disable two-factor authentication for selected users in Remote Administration.
Companies around the world are faced with the need to manage email access after hours to reduce overtime pay and promote a stronger work/life balance for their employees. MDaemon makes this goal attainable using its Do Not Disturb feature. Do Not Disturb allows administrators to designate a time during which selected users are not allowed to check their email. During the Do Not Disturb period, accounts can still receive email on the mail server, but users cannot send or check for mail using SMTP, IMAP, POP, WorldClient or ActiveSync.
In MDaemon, you can access the Do Not Disturb feature via the Group Manager screen under the Accounts menu. Follow these steps to configure Do Not Disturb.
Select Groups & Templates.
Select Group Manager.
Select New Group or click on an existing group to select it. Enter a Group Name and Description for your new group.
Click on Add or remove accounts from the selected group.
Check the box for each account you wish to add to this group, and then click OK.
Select the group name under the Group Manager list.
Check Enable Do Not Disturb.
Click on Define Do Not Disturb Schedule to configure when you would like this feature to take effect.
Select your desired Do-Not-Disturb schedule, including dates, times, and days of the week, and then click OK.
Click OK to close the Groups & Templates window.
Once these settings are enabled, users who try to access or send email during Do Not Disturb hours will be denied access.
The following video demonstrates how to configure Do Not Disturb.
Do Not Disturb gives administrators and management teams greater control over who has after-hours access to the email system. This feature was added in MDaemon 15.5. If you’re using an older version of MDaemon and would like to upgrade, then visit our Downloads page to download the latest version of MDaemon.
IMPORTANT NOTE: This promotion is for Alt-N customers and resellers who work directly with Alt-N. MailStore uses other Alt-N Distribution partners in various countries for sales and you should check your country for specific sales by visiting the MailStore partner page
Be sure to take advantage of these offers today!
* Promotions cannot be combined and you must meet the 50% upgrade offer requirements. 20% offer expires March 31, 2016.
If you’re moving to MDaemon from another email platform, or if you want to consolidate your local address books into one centrally-located database for easy access from anywhere, then you’ll want to import your contacts using WorldClient.
When contacts are imported into WorldClient, they are stored in a folder on the MDaemon server and accessible from your ActiveSync-connected mobile device (or Outlook 2013 & up connected via ActiveSync), Outlook via Outlook Connector, and WorldClient – MDaemon’s webmail client.
For spammers, the barriers to entry are very low and the potential payoffs are very high relative to the small amounts of effort required to send out lots of spam. Spammers typically look for the “low hanging fruit” of an email system, such as mail servers that are not configured to prevent relaying, or accounts with weak passwords. If a hacker manages to guess an account’s password, he can use that account to send out large amounts of unsolicited spam email messages. This can result in your server winding up on a blacklist. Additionally, if large amounts of spam are sent out before the issue is corrected, your business can suffer lost trust and a reduction in revenue.
MDaemon’s Account Hijack Detection feature can be used to disable the account once a specified number of messages have been sent from an authenticated session within a given period of time. But it would be better to not even let a hacker get that far. Having strong passwords that are difficult to guess would help prevent an account from being hijacked in the first place.
Today, we focus on the issue of weak passwords and how to thwart hackers by implementing strong password policies. These settings are located in MDaemon under the Accounts | Account Settings configuration screen. In today’s video tutorial, we demonstrate how to require strong passwords, how to force accounts with a weak password to change their password, and how to send a Weak Passwords report to a designated email address.
Email is one of the most valuable intellectual property assets a company can have. Protect your email by enacting strong security and password policies & keep the hackers out.
Recently, I created a video and blog post about Virtru Email Encryption for MDaemon, to demonstrate its features, benefits, and ease of use. Following along with its ease of use, I’ve created the following animation to show you just how easy Virtru is to use. Simply enable Virtru support in WorldClient (MDaemon’s webmail client), enable the Virtru features by clicking on the small “V” button within the email compose window, and then click on “Send Encrypted.” It really is that simple!
MDaemon 15.5.3 has been released. With this latest release, we’ve added support for one of the most popularly-requested features – the ability for the content filter to check for restricted files inside of RAR and ZIP attachments.