How are spammers getting content for their spam emails?

Key findings

• Content reuse: Spammers frequently copy content directly from legitimate mailing lists, newsletters, or web-hosted versions of email campaigns. This saves them effort in content creation and allows them to mimic trusted brands.
• Header manipulation: They often forge email headers, particularly the Received lines, to obscure the true origin of the email. Only the last Received header can typically be trusted.
• BCC exploitation: Spammers widely use the Blind Carbon Copy (BCC) function. They place the actual recipient's email in the RCPT TO command during the SMTP transaction, but use a random or decoy address in the visible To: header.
• Automated harvesting: Sophisticated tools and bots crawl the internet, including publicly available websites and social media, to harvest email addresses and content for mass spamming campaigns. This process is known as email harvesting.
• Malicious intent: Emails containing repurposed or seemingly legitimate content almost always lead to malicious payloads, such as phishing scams, malware downloads, or other fraudulent activities. Understanding these risks is crucial for protecting your inbox, especially when dealing with unusual emails, and recognizing email spam traps.

Key considerations

• Email header analysis: Regularly analyzing email headers can help identify the true sending source and detect signs of spoofing or malicious intent. This is especially important for recognizing spam.
• Content authentication: While spammers may copy content, legitimate senders should always ensure their emails are properly authenticated with SPF, DKIM, and DMARC to prevent impersonation and improve deliverability.
• Awareness of tactics: Being aware of common spammer tactics, such as the use of decoy To: addresses and forged headers, can help users and email service providers better identify spam.
• Reporting spam: Reporting suspicious emails as spam helps email providers train their filters and block future malicious campaigns. The Federal Trade Commission (FTC) offers guidance on how to manage unwanted emails.
• Protecting public information: Exercising caution when posting email addresses or other personal information online can help reduce exposure to harvesting tools used by spammers. Consider the risks of sending emails to scraped lists.

Key opinions

• Misleading 'To' fields: Marketers frequently notice spam emails addressed to generic or unrelated AOL accounts, like Dustin@aol.com or Dennis@aol.com, while the actual recipient is BCC'd. This is a common spamming technique.
• Content mimicry: There is a concern among marketers that spammers are directly copying content from their legitimate campaigns. This raises questions about how spammers acquire these materials, whether through subscribing to lists or scraping web versions.
• Spamware patterns: Some spammers use automated software that pulls batches of email addresses, typically from alphabetically sorted lists, sending to all via BCC while using the first address in the visible 'To' header.
• Payload suspicion: Marketers rightly suspect that clicking through links in these seemingly familiar but unsolicited emails would lead to malicious outcomes, such as phishing or malware.
• Header and content junk: Observations include heavily munged or copy-pasted headers from legitimate ESP emails, and often thousands of lines of junk text hidden within HTML tags.

Key considerations

• Proactive junking: For individual recipients, the most straightforward action is to immediately mark such emails as junk or spam to help train their email provider's filters.
• Header vigilance: Marketers and users should be vigilant about checking email headers for discrepancies, as this can reveal the true, often deceptive, sending practices. This helps to determine if marketing emails are going to spam.
• Authentication standards: Ensuring robust email authentication (SPF, DKIM, DMARC) is critical for legitimate senders to minimize the ability of spammers to impersonate their domain and prevent emails from going to spam.
• Content protection: While difficult to prevent completely, marketers can consider strategies to make it harder for spammers to scrape and reuse their content, such as dynamic content generation or specific display rules.
• Filter awareness: Understanding how spam filters work and the phrases or patterns that trigger them can help legitimate marketers improve their own deliverability while recognizing spammer tactics.

Key opinions

• Header analysis is key: Experts advise that inspecting email headers is the first step to understanding how spam is routed and identifying any anomalies. They point out that only the last Received header can be reliably trusted, as others are often forged.
• BCC functionality exploitation: Many spammers leverage the BCC feature by connecting to systems and placing the recipient's address in the RCPT TO: command during the transaction, while using a random address in the visible To: header. This is a common spamware pattern.
• Snowshoe spamming: Some IP ranges associated with spam show characteristics of snowshoe spam, where small volumes of email are sent from a large number of IPs to evade detection. Monitoring your blocklist status can help detect this.
• Content sourcing: Spammers are likely obtaining content by subscribing to legitimate mailing lists or scraping web-hosted versions of newsletters and then repurposing them.
• Malicious payloads: It is almost certain that links within these spam emails lead to malicious activities, such as phishing or malware, despite their seemingly innocuous content or branding.

Key considerations

• Deep header analysis: Understanding and analyzing complex email headers, including forged lines, is crucial for identifying sophisticated spam campaigns and their origins.
• Sender authentication: While authentication might not stop content reuse, strong SPF, DKIM, and DMARC policies are essential to prevent direct impersonation and make it harder for spammers to deliver messages purporting to be from a legitimate domain.
• Spam reporting: Consistently reporting spam, even when it appears to contain legitimate content, helps mailbox providers improve their filters and block malicious senders. You can also monitor your domain reputation to see the impact of spam campaigns.
• Awareness of spam patterns: Understanding common patterns like the use of random 'To' addresses, junk text within HTML, and forged headers helps in rapid identification of spam.
• Proactive defense: As noted by Guardian Digital, email address harvesting is a core spam tactic. Organizations should consider security measures to protect publicly listed email addresses.

Key findings

• Email harvesting: Documentation consistently points to email harvesting as a primary method for spammers. This involves using automated tools (spambots) to crawl websites, public forums, and social media for email addresses.
• Sophisticated tools: Spammers utilize advanced software to scan the web and gather addresses and potentially content. If an email address is publicly available, it's vulnerable to these tools.
• Social engineering: Beyond automated collection, documentation highlights spammers' use of social engineering. This means they research targets and craft content designed to exploit psychological vulnerabilities, making their emails more convincing.
• Content triggers: Documentation from email service providers often lists certain phrases or content patterns that commonly trigger spam filters, which spammers typically try to avoid or adapt their content around.
• Phishing content: The FTC provides extensive documentation on how scammers use email and text messages with deceptive content to trick recipients into revealing personal and financial information. This content is designed to appear urgent or official.

Key considerations

• Privacy settings: Reviewing and strengthening privacy settings on social media and other online platforms can limit the visibility of email addresses to harvesting bots.
• Email obfuscation: When an email address must be displayed publicly, documentation suggests using methods like replacing @ with 'at' or using JavaScript to render the address, making it harder for bots to scrape.
• Educating users: Awareness campaigns for employees and customers about recognizing phishing attempts and malicious content are critical. The FTC provides resources on identifying and avoiding scams.
• Domain reputation management: Legitimate organizations should continuously monitor their email domain reputation and maintain proper email authentication to avoid being mistaken for spammers.
• Spam trap avoidance: Documentation, such as from Microsoft, explains that spammers use sophisticated tools to scan the web and harvest addresses, including those that might be spam traps. Senders should clean lists to avoid these.