Hide Artifacts: Ignore Process Interrupts
Other sub-techniques of Hide Artifacts (12)
Adversaries may evade defensive mechanisms by executing commands that hide from process interrupt signals. Many operating systems use signals to deliver messages to control process behavior. Command interpreters often include specific commands/flags that ignore errors and other hangups, such as when the user of the active session logs off.(Citation: Linux Signal Man) These interrupt signals may also be used by defensive tools and/or analysts to pause or terminate specified running processes. Adversaries may invoke processes using `nohup`, PowerShell `-ErrorAction SilentlyContinue`, or similar commands that may be immune to hangups.(Citation: nohup Linux Man)(Citation: Microsoft PowerShell SilentlyContinue) This may enable malicious commands and malware to continue execution through system events that would otherwise terminate its execution, such as users logging off or the termination of its C2 network connection. Hiding from process interrupt signals may allow malware to continue execution, but unlike Trap this does not establish Persistence since the process will not be re-invoked once actually terminated.
Примеры процедур |
|
| Название | Описание |
|---|---|
| GoldMax |
The GoldMax Linux variant has been executed with the `nohup` command to ignore hangup signals and continue to run if the terminal session was terminated.(Citation: CrowdStrike StellarParticle January 2022) |
| OSX/Shlayer |
OSX/Shlayer has used the `nohup` command to instruct executed payloads to ignore hangup signals.(Citation: Shlayer jamf gatekeeper bypass 2021) |
| BPFDoor |
BPFDoor set's it's process to ignore the following signals; `SIGHUP`, `SIGINT`, `SIGQUIT`, `SIGPIPE`, `SIGCHLD`, `SIGTTIN`, and `SIGTTOU`.(Citation: Deep Instinct BPFDoor 2023) |
Ссылки
- Microsoft. (2023, March 2). $DebugPreference. Retrieved August 30, 2023.
- Meyering, J. (n.d.). nohup(1). Retrieved August 30, 2023.
- Linux man-pages. (2023, April 3). signal(7). Retrieved August 30, 2023.
- CrowdStrike. (2022, January 27). Early Bird Catches the Wormhole: Observations from the StellarParticle Campaign. Retrieved February 7, 2022.
- Jaron Bradley. (2021, April 26). Shlayer malware abusing Gatekeeper bypass on macOS. Retrieved September 22, 2021.
- Shaul Vilkomir-Preisman and Eliran Nissan. (2023, May 10). BPFDoor Malware Evolves – Stealthy Sniffing Backdoor Ups Its Game. Retrieved September 19, 2024.
Связанные риски
Каталоги
Мы используем cookie-файлы, чтобы получить статистику, которая помогает нам улучшить сервис для вас с целью персонализации сервисов и предложений. Вы может прочитать подробнее о cookie-файлах или изменить настройки браузера. Продолжая пользоваться сайтом, вы даёте согласие на использование ваших cookie-файлов и соглашаетесь с Политикой обработки персональных данных.