Hackers are getting wise to the fact that a lot of people are working from home due to the coronavirus pandemic and are seeking to take advantage of that fact by calling individuals and pretending to be IT workers from their companies, trying to trick the individuals into divulging sensitive and confidential information.
The Federal Bureau of Investigation and the U.S. Cybersecurity and Infrastructure Security Agency issued a joint warning last week, saying that the criminals are “highly aggressive” in how they are monetizing their attacks and are being “indiscriminate” in the size and types of companies that they are attacking.
The news comes a week after it was revealed that a revenue cycle management company was the victim of a ransomware attack, which may have been caused by a phishing scam.
In launching the attack, the perpetrators were deploying sophisticated methods and doing a lot of homework. The scammers “compiled dossiers” on individuals by checking their social media profiles and pulling information from publicly available background checks. They would then register domains and set up phishing pages to duplicate a company’s VPN login, allowing them to capture two-factor authentication and one-time passwords from unsuspecting individuals.
THe FBI and CISA offered organizations a number of tips, including:
- Restricting VPN connections to managed devices only, using mechanisms like hardware checks or installed certificates, so user input alone is not enough to access the corporate VPN.
- Restrict VPN access hours, where applicable, to mitigate access outside of allowed times.
- Employ domain monitoring to track the creation of, or changes to, corporate, brand-name domains.
- Actively scan and monitor web applications for unauthorized access, modification, and anomalous activities.
- Employ the principle of least privilege and implement software restriction policies or other controls; monitor authorized user accesses and usage.
- Consider using a formalized authentication process for employee-to-employee communications made over the public telephone network where a second factor is used to authenticate the phone call before sensitive information can be discussed.
- Improve 2FA and OTP messaging to reduce confusion about employee authentication attempts.
Employees, meanwhile, should:
- Verify web links do not have misspellings or contain the wrong domain.
- Bookmark the correct corporate VPN URL and do not visit alternative URLs on the sole basis of an inbound phone call.
- Be suspicious of unsolicited phone calls, visits, or email messages from unknown individuals claiming to be from a legitimate organization. Do not provide personal information or information about your organization, including its structure or networks, unless you are certain of a person’s authority to have the information. If possible, try to verify the caller’s identity directly with the company.
- If you receive a vishing call, document the phone number of the caller as well as the domain that the actor tried to send you to and relay this information to law enforcement.
- Limit the amount of personal information you post on social networking sites. The internet is a public resource; only post information you are comfortable with anyone seeing.
- Evaluate your settings: sites may change their options periodically, so review your security and privacy settings regularly to make sure that your choices are still appropriate.