Mithril Emmet

Problem

Uniform Resource Locators (URLs) are structured addresses that point to locations and assets on the internet. URLs allow software developers to build complex applications that exchange data with servers that can be hosted in multiple geographical regions. URLs can commonly be found embedded in documentation, configuration files, source code and compiled binaries. One or more embedded URLs were discovered to link to raw files hosted on GitHub. Attackers often abuse popular web services to host malicious payloads. Since code-sharing services URLs are typically allowed by security solutions, using them for payload delivery increases the odds that the malicious code will reach the user. While the presence of code-sharing service locations does not imply malicious intent, all of their uses in a software package should be documented and approved. An increasing number of software supply chain attacks in the open source space leverages the GitHub service to deliver malicious payloads.

Problem

Unicode is a text encoding standard designed to support the use of text written in all of the major languages and writing systems. While most languages are written from left to right, some are written in alternative directions. To accommodate encoding text written in such languages, the Unicode standard includes a number of special characters that allow the text direction to be specified. However, changing text direction can have adverse effects on how the encoded text is displayed and interpreted. For this reason, bidirectional Unicode control characters are commonly abused by malicious actors as a means of bypassing security solutions and avoiding detection. While presence of special Unicode characters does not imply malicious intent, all of its uses in a software package should be documented and approved. One example of acceptable use for these special characters is in script files that parse, validate, and transform Unicode-encoded text.