RedKrypt Ransomware

Product Serial: B-2022-10-20b

TLP:AMBER

In this brief, ZeroFox Intelligence shares details on a recently discovered ransomware family calling itself RedKrypt.

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DDW MAL

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Scope Note

ZeroFox Intelligence is derived from a variety of sources, including—but not limited to—curated open-source accesses, vetted social media, proprietary data sources, and direct access to threat actors and groups through covert communication channels. Information relied upon to complete any report cannot always be independently verified. As such, ZeroFox applies rigorous analytic standards and tradecraft in accordance with best practices and includes caveat language and source citations to clearly identify the veracity of our Intelligence reporting and substantiate our assessments and recommendations. All sources used in this particular Intelligence product were identified prior to 08:00 AM (EDT) on October 18, 2022; per cyber hygiene best practices, caution is advised when clicking on any third-party links.

Executive Summary

ZeroFox Intelligence has discovered a previously-unknown ransomware family calling itself RedKrypt. Not much is known about its infection vector, as the sample was discovered on VirusTotal. The ransomware was created in Microsoft's .NET framework and does not appear to use any sort of obfuscation. One key is generated per victim, and that key is then encrypted via RSA1024. Plaintext (.txt) and Markdown (.md) files are fully encrypted, while all other files are only encrypted up to the first 1024 bytes. To ensure it can recover a victim's files, RedKrypt sends the operators a uniquely-generated ID and a RSA1024 private key via Telegram.