Pagers are still used in industrial environments and many organizations don’t realize that the messages sent with these devices can be highly useful to malicious actors looking to launch a targeted attack.
After analyzing the use of pagers in the healthcare industry, researchers at Trend Micro have focused their attention on the risk they pose to industrial environments, particularly in critical infrastructure sectors.
Industrial control systems (ICS) can rely on pagers to transmit information that is crucial for the operation of a facility, including events and deviations in the production process. Pagers are particularly popular as backup communication systems and in areas where cellular coverage is weak.
The problem is that the messages sent to these devices are typically unencrypted, allowing anyone with the technical knowhow and some inexpensive equipment to intercept the information.
Over a 4-month period, Trend Micro captured nearly 55 million pages sent in the United States and Canada, roughly one-third of which contained alphanumeric data. This can be considered a high quality source of passive intelligence since the data can include alarm or event notifications, diagnostics information, facility-related status updates, names, email addresses, phone numbers, project codes, and IP addresses.
This type of information can be highly useful for social engineering attacks, and even for lateral movement once the targeted network has been compromised.
Researchers analyzed messages sent by nuclear plants, power substations, chemical companies and defense contractors. Firms specializing in semiconductors, commercial printing and HVAC have also been found to leak potentially sensitive data via pagers.
Information from pages, which are often sent via email-to-pager or SMS-to-pager gateways, can be used for various purposes, as explained by Trend Micro in its report:
“Knowledge of issues within the plant, like minor mechanical failures, etc. can be creatively used by determined attackers to craft social engineering attacks that will appear highly believable because of prior reconnaissance. Depending on the attacker’s goal, one possible way for an attacker to get in is by scheduling a delivery that is timed with the scheduled arrival of a replacement part. Another way is to simply send an email containing a remote access Trojan to the maintenance department with relevant word tokens.
Information about a company’s high-ranking employees, like names, email addresses and phone numbers, can be used to directly craft social engineering attacks.
While some information types are the same across more than one sector, the possible applications of a planned attack may be different depending on the nature of the sector involved. Less likely but also plausible, would be for highly skilled attackers to make use of the specific issues inside, for instance, a nuclear plant, to trigger some form of sabotage, after they have gained physical access.”