A number of zero-day vulnerabilities that were addressed last year were exploited by commercial spyware vendors to target Android and iOS devices, Google’s Threat Analysis Group (TAG) has revealed.

The two distinct campaigns were both limited and highly targeted, taking advantage of the patch gap between the release of a fix and when it was actually deployed on the targeted devices.

“These vendors are enabling the proliferation of dangerous hacking tools, arming governments that would not be able to develop these capabilities in-house,” TAG’s Clement Lecigne said in a new report.

“While use of surveillance technologies may be legal under national or international laws, they are often found to be used by governments to target dissidents, journalists, human rights workers, and opposition party politicians.”

The first of the two operations took place in November 2022 and involved sending shortened links over SMS messages to users located in Italy, Malaysia, and Kazakhstan.

Upon clicking, the URLs redirected the recipients to web pages hosting exploits for Android or iOS, before they were redirected again to legitimate news or shipment-tracking websites.

The iOS exploit chain leveraged multiple bugs, including CVE-2022-42856 (a then zero-day), CVE-2021-30900, and a pointer authentication code (PAC) bypass, to install an .IPA file onto the susceptible device.

The Android exploit chain comprised three exploits – CVE-2022-3723, CVE-2022-4135 (a zero-day at the time of abuse), and CVE-2022-38181 – to deliver an unspecified payload.

While CVE-2022-38181, a privilege escalation bug affecting Mali GPU Kernel Driver, was patched by Arm in August 2022, it’s not known if the adversary was already in possession of an exploit for the flaw prior to the release of the patch.

Another point of note is that Android users who clicked on the link and opened it in Samsung Internet Browser were redirected to Chrome using a method called intent redirection.

The second campaign, observed in December 2022, consisted of several zero-days and n-days targeting the latest version of Samsung Internet Browser, with the exploits delivered as one-time links via SMS to devices located in the U.A.E.

The web page, similar to those that were used by Spanish spyware company Variston IT, ultimately implanted a C++-based malicious toolkit capable of harvesting data from chat and browser applications.

The flaws exploited constitute CVE-2022-4262, CVE-2022-3038, CVE-2022-22706, CVE-2023-0266, and CVE-2023-26083. The exploit chain is believed to have been used by a customer or partner of Variston IT.

That said, the scale of the two campaigns and the nature of the targets are currently unknown.

The revelations come just days after the U.S. government announced an executive order restricting federal agencies from using commercial spyware that presents a national security risk.

“These campaigns are a reminder that the commercial spyware industry continues to thrive,” Lecigne said. “Even smaller surveillance vendors have access to zero-days, and vendors stockpiling and using zero-day vulnerabilities in secret pose a severe risk to the Internet.”

“These campaigns may also indicate that exploits and techniques are being shared between surveillance vendors, enabling the proliferation of dangerous hacking tools.”