APT28 Attacks Webmail and Microsoft Exchange Servers to Launch Sophisticated Spear Phishing Attacks

Pawn Storm having a group also known as APT28, Strontium, and Fancy Bear active since at least 2004, the group has targeted many organizations globally.

The threat actors behind the hacking group use sophisticated social engineering lures, data-stealing malware, several zero-days, and even a private exploit kit.

Attack on Webmail servers

According to a new report from Trend Micro, the hacker group searches for vulnerable mail servers, for the past 2 years to launch sophisticated phishing campaigns.

Starting from 2019 the group probes on several email servers and Microsoft Exchange services around the world.

Threat actors aimed at TCP port 443 (used by webmail and Microsoft Exchange Autodiscover services), IMAP port (143, 993), PoP3 port (110, 995) and SMTP port(465, 587) are checked.

The attack was conducted aiming to exfiltrate data such as vulnerable systems, brute force credentials, exfiltrate email data, and send out spam waves.

Researchers observed an instance in which the hacked email used to send spam messages for several high-profile targets.

The threat actor group abuses the Email address of several different industry sectors to send the phishing spam.

“For over two years, we were able to observe a significant number of Pawn Storm’s credential phishing campaigns through careful analysis of DNS SPF (Sender Policy Framework) requests of the domains they used,” reads the report.

The following are the Pawn Storm’s typical targets from August 2019 to November 2019.

The group uses this attack scheme for an extensive period between 2019 to 2020, they used the email account of defense companies belonging to the Middle east.

For all the campaigns the group leverages the OpenVPN option of commercial VPN service providers to connect to a dedicated host that sends out spam.

The Pawn Strom is the most popular group that uses a wide range of tools and tactics they continue to be active for years to come. Organizations must secure their parameters to reduce risk.