As we continue to bring awareness to these threats, new ones emerge almost daily. In the past three months, a cyber-espionage group known as Seedworm (aka MuddyWater) has used spear-phishing attacks to infect 131 individuals with the Powermuddy backdoor (a new variant of their Powermud backdoor). Once a system has been compromised, this malware runs a tool that steals passwords from a user’s browser and email, often leading to access to the victim’s email and social media accounts.
Protect Yourself from the Latest Threats
Over the years, I’ve posted many times about phishing, spear-phishing, and other threats, with a variety of suggestions for protecting yourself and your business from becoming the next victim. Throughout these posts (from oldest to newest), you’ll find lots of tips to avoid being tricked by these email-borne scams.
As the threat landscape continues to evolve, businesses of all sizes must maintain awareness of the latest email-borne threats and educate staff at all levels, from entry level to C-suite. After all, without the right tools and procedures in place, it only takes one misguided mouse click to damage a business’ reputation or send it into bankruptcy.
This week, we continue our series on Business Email Compromise. Click here to read Part 1, which includes an overview and various statistics on this growing threat.
It takes time and effort to launch a successful Business Email Compromise (BEC) attack. In a typical attack, several messages are exchanged in an attempt to convince the target to authorize large payments to the attacker’s bank account. From start to finish, the steps involved in a BEC attack consist of identifying a target, grooming, exchanging information, and finally, transfer of funds.
Let’s go over these four steps in detail.
Step 1 – Identify the Target Victim
The first step in a BEC attack may be the most time-consuming. During this step, a criminal organization researches the victim to develop an accurate profile of the company. Through publicly available information, attackers look for the names and positions of company executives, especially those on the finance team. They scour social media, online articles, and anything else that will provide specific details about the company and its employees. Scammers who are able to infiltrate a company’s network with malware may spend weeks or months monitoring information on the company’s vendors, billing and payment systems, and employee vacation schedules. They have also been known to monitor the executive’s writing style in order to craft a convincing email using a spoofed email address or lookalike domain claiming to come from the CEO.
Step 2 – Grooming
Armed with the information obtained in Step 1, the scammer moves on to Step 2. During this step, the scammer uses spear-phishing, phone calls or other social engineering tactics to target employees with access to company finances. The grooming phase often takes several days of back and forth communication in order to build up trust. During this phase, the scammer may impersonate the CEO or another company executive and use his or her authority to pressure the employee to act quickly.
Here is an example sent to one of our Finance executives in which the sender used display name spoofing to spoof the name of our CEO. Cybercriminals will often use a free email address (notice the comcast.net domain), which can be easy to miss if you’re using a mobile device or some other client that doesn’t display the full email header.
Step 3 – Exchange of Information
During step 3, the victim is convinced that he is conducting a legitimate business transaction, and is then provided with wire transfer instructions.
Step 4 – Payment
And finally, funds are transferred and deposited into a bank account controlled by the criminal organization.
What to Do if You Are a Victim
If you’ve suffered losses due to Business Email Compromise schemes, it is important to act quickly.
Contact your financial institution immediately.
Request your financial institution contact the institution that received the fraudulent funds.
Contact your local FBI office and report the incident.
Scammers use a variety of tactics to get users to give out personal information. One very common tactic is known as phishing. Phishing is a scam where tech-savvy con artists use spam and malicious websites to deliver malware, or to trick people into giving them personal information such as social security numbers, bank account numbers, and credit card information. A more targeted (and often more dangerous) type of phishing is known as spear phishing.
What is Spear Phishing?
Spear phishing is a targeted attack that’s usually addressed to a specific individual. With spear phishing, the perpetrator knows something personal about you. He may know your name, email address, or the name of a friend, or he may have information about a recent online purchase you made. While most phishing emails will have a generic greeting such as “Dear Sir or Madam,” a spear phishing email may address you by name, such as “Hello John.” It may also appear to come from someone you know.
According to Allen Paller, director of research at the SANS Institute, 95% of all attacks on enterprise networks are the result of spear phishing attacks. Earlier this year, Symantec issued a warning about an ongoing spear phishing attack targeting small and midsize businesses in the United States, India, and the UK that infects users with a remote access Trojan (RAT). A RAT gives an attacker remote access to a machine & can lead to disclosure of sensitive information and financial losses. Based on campaigns run by Symantec’s Phishing Readiness technology, on average, employees are susceptible to email-based attacks 18 percent of the time.
How can You Protect Yourself & Your Business?
Protecting your company from spear phishing attacks is the responsibility of employees as well as the mail server administrator. For employees, user education is key. This post contains helpful email safety tips for end users. For the administrator, implementing DKIM, SPF and DMARC can help reduce data breaches, financial losses, and other threats to your business. These three methods are described in greater detail below.
How DKIM Works
DKIM (DomainKeys Identified Mail) is a cryptographic email verification system that can be used to prevent spoofing. It can also be used to ensure message integrity, or to ensure that the message has not been altered between the time it left the sending mail server and the time it arrived at yours. Here’s how DKIM works:
An encrypted public key is published to the sending server’s DNS records.
Each outgoing message is signed by the server using the corresponding encrypted private key.
For incoming messages, when the receiving server sees that a message has been signed by DKIM, it will retrieve the public key from the sending server’s DNS records and then compare that key with the message’s cryptographic signature to determine its validity.
If the incoming message cannot be verified then the receiving server knows it contains a spoofed address or has been tampered with or changed. A failed message can then be rejected, or it can be accepted but have its spam score adjusted.
You can refer to the following knowledge base article for DKIM setup instructions in MDaemon:
Another technique to help prevent spoofing is known as SPF. SPF (Sender Policy Framework) allows domain owners to publish DNS records (SPF records) to identify those locations authorized to send messages for their domain. By performing an SPF lookup on incoming messages, you can attempt to determine whether or not the sending server is permitted to deliver mail for the purported sending domain, and consequently determine whether or not the sender’s address may have been forged or spoofed.
MDaemon’s SPF settings are located under Security | Security Settings | Sender Authentication | SPF Verification. This screenshot displays the recommended settings.
Recommended SPF settings for SecurityGateway are outlined in this knowledge base article:
These are the recommended settings for verifying SPF records of other domains. To help protect against spear phishing attacks that spoof your own domain, you should set up an SPF record in DNS. You can find helpful information on SPF record syntax and deployment at www.openspf.org.
When a message fails DKIM or SPF, it is up to the receiving mail server’s administrator as to how to handle the message. The problem with this is that if DKIM or SPF is not set up properly, it can lead to problems. DMARC (Domain-based Message Authentication, Reporting and Conformance) takes out the guesswork on how to handle messages from a domain that are not properly aligned with DKIM or SPF.
DMARC defines a scalable mechanism by which a mail sender can express, using DNS records (DMARC records), domain level policies governing how messages claiming to come from his or her domain should be handled when they do not fully align with DKIM and SPF lookup results. In other words, if you perform SPF, DKIM and DMARC record lookups on a message claiming to come from my domain (example.com), and it does not align with SPF, DKIM, or both, my DMARC record can tell you how I want you to handle messages that are unaligned with SPF & DKIM. My DMARC record can specify whether I want you to accept, quarantine, or reject unaligned messages, and I can even go a step further and specify what percentage of unaligned messages I want you to reject or quarantine based on my policy preferences. This is useful when first deploying DMARC, as it allows you to be more lenient with rejection of unaligned messages until you’re sure DKIM & SPF are configured properly.
You can view the following recorded webinar for a more in-depth overview of DMARC, including examples and syntax of DMARC records and deployment strategy.
While we must be vigilant against spoofing and phishing attacks, we must also acknowledge that cautious, informed users and properly implemented SPF, DKIM and DMARC policies are the best defense against cybercriminals who are intent on stealing your data and damaging your brand.