Cybercriminal gangs operating in Nigeria have been discovered to be using phishing kits in a highly sophisticated phishing campaign that has seen millions of dollars obtained from big businesses.
The scammers are regularly fooling employees into revealing their email login credentials – The first stage of the complex scam. The ultimate goal of the attackers is to gain access to corporate bank accounts and convince accounts department employees to make sizeable transfers to their accounts.
According to research conducted by IBM, these scams have been highly successful. Fortune 500 companies are being targeted and losses have been estimated to be of the order of several million dollars.
These scams take time to pull off and considerable effort is required on the part of the scammers. However, the potential rewards are worth the effort. Bank transfers of tens or hundreds of thousands of dollars can be made and business email accounts can be plundered.
A Sophisticated Multi-Stage Phishing Scam
In order to pull off the scam, the attackers must first gain access to at least one corporate email account. Access is gained using phishing emails, with social engineering tactics used to convince employees to click on a malicious link. Those links direct the email recipients to malicious DocuSign login pages where credentials are harvested. These malicious pages have been created on multiple websites.
According to IBM, the gang behind this campaign has created more than 100 of these pages, many of which have been loaded onto genuine websites that have been compromised by the attackers.
Once access to one email account is gained, it is easy to obtain email addresses from the contact list to fool other employees. When an email account is accessed, the attackers search the account for messages involving accounts and payments. The attackers then send emails carrying on conversations between staff members, inserting themselves into conversations and continuing active discussions.
“The attackers typically took a week between the point they gained initial access to a user’s email account and the time they started setting up the infrastructure to prepare a credible ruse,” said IBM’s X-Force researchers. “During this time, they likely conducted extensive research on the target’s organizational structure, specifically focusing on the finance department’s processes and vendors.”
By setting up email rules and filters, it is possible to block genuine conversations between the employees that could uncover the scam. By doing this, all conversations take place between a specific individual and the attacker.
This method of attack allows the attackers to gain access to banking credentials and send highly convincing emails requesting transfers to their accounts. Targeted employees are unlikely to be unaware that they are not emailing a legitimate contact.
This is a manual, labor-intensive scam involving no malware. That has the advantage of allowing the attackers to evade anti-malware technologies.
How to Protect Against These Sophisticated Email Scams
While these scams are complex, they start with a simple phishing email to gain access to a corporate email account. Once access to an email account has been gained, stopping the scam becomes much harder. The easiest time to prevent such an attack is at the initial stage, by preventing the phishing emails from reaching the inboxes of employees and training employees how to identify phishing emails.
That requires an advanced spam filtering solution that can identify the common signatures of spam and scam emails. By setting aggressive filtering policies, the vast majority of spam emails will be captured and quarantined. With the SpamTitan cloud-based anti-spam service, that equates to more than 99.9% of all spam and malicious emails. SpamTitan also has a particularly low false positive rate – less than 0.03% – ensuring genuine emails are still delivered.
No spam solution can be 100% effective, so it is also important to prepare the workforce and train staff how to identify malicious emails. Security awareness and anti-phishing training allows organizations to create a ‘human firewall’ to complement technical solutions.
Spear phishing – highly targeted email attacks – are harder to block, but it is possible to implement solutions to prevent scams such as this from resulting in credentials being obtained. In this campaign, links are sent in emails. By implementing a web filtering solution, those links can be blocked. In tandem with a spam filter, organizations with a security aware workforce will be well protected from phishing attacks.
Further, the use of two-factor authentication is an important security measure to implement. This will prevent attackers from using an unknown device to access an email account.
For further information on web filters and spam filters, and the benefits of installing them at your organization, contact the TitanHQ team today and take the first step toward improving your defenses against sophisticated phishing scams.