Attacks launched recently against financial and government organizations in Asia leveraged a zero-day vulnerability in the InPage word processor, Kaspersky Lab reported on Wednesday.
InPage is a word processor for languages such as Urdu, Persian, Pashto and Arabic. The product is widely used in Asia and some other parts of the world, including by media companies, academies, libraries, banks and government organizations.
While analyzing a target that had been hit with various types of exploits, Kaspersky Lab researchers discovered an exploit file that had an InPage (.inp) extension. The file contained a shellcode that was triggered on several InPage versions. The shellcode decrypts itself and an EXE file embedded in the malicious document.
“InPage uses its own proprietary file format that is based on the Microsoft Compound File Format. The parser in the software’s main module ‘inpage.exe’ contains a vulnerability when parsing certain fields. By carefully setting such a field in the document, an attacker can control the instruction flow and achieve code execution,” explained Kaspersky researcher Denis Legezo.
In the attacks observed by the security firm, threat groups sent spear-phishing emails carrying the InPage exploit to various government and financial institutions in Asia and Africa, in countries such as Myanmar, Sri-Lanka and Uganda. Since the exploit has been leveraged to deliver various backdoors and keyloggers, researchers believe the zero-day has likely been used by multiple actors.
Kaspersky said it had attempted to inform InPage about the zero-day, but without success. SecurityWeek has reached out to InPage developers and will update this article if they provide any information.
While threat actors typically leverage vulnerabilities in software used worldwide (e.g. Microsoft Office), flaws in products such as InPage can also be highly useful for more localized and targeted attacks. Another example is the Hangul Word Processor (HWP), which is popular in South Korea.
Last year, experts reported that a zero-day in HWP had been used in attacks launched by an actor believed to be associated with North Korea. However, unlike InPage, the developers of HWP seem to be more interested in security and they often release updates that patch vulnerabilities.
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