Query: SIEM correlation: stealth activity consistent with Debugger Evasion
Matching passage: T1622 Debugger Evasion. Tactics: stealth, discovery. Description: Adversaries may employ various means to detect and avoid debuggers. Debuggers are typically used by defenders to trace and/or analyze the execution of potential malware payloads.(Citation: ProcessHacker Github) Debugger evasion may include changing behaviors based on the results of the checks for the presence of artifacts indicative of a debugged environment. Similar to [Virtualization/Sandbox Evasion](https://attack.mitre.org/techniques/T1497), if the adversary detects a debugger, they may alter their malware to disengage from the victim or conceal the core functions of the implant. They may also search for debugger artifacts before dropping secondary or additional payloads. Specific checks will vary based on the target and/or adversary. On Windows, this may involve [Native API](https://attack.mitre.org/techniques/T1106) function calls such as <code>IsDebuggerPresent()</code> and <code> NtQueryInformationProcess()</code>, or manually checking the <code>BeingDebugged</code> flag of the Process Environment Block (PEB). On Linux, this may involve querying `/proc/self/status` for the `TracerPID` field, which indicates whether or not the process is being traced by dynamic analysis tools.(Citation: Cado Security P2PInfect 2023)(Citation: Positive Technologies Hellhounds 2023) Other checks for debugging artifacts may also seek to enumerate hardware breakpoints, interrupt assembly opcodes, time checks, or measurements if exceptions are raised in the current process (assuming a present debugger would “swallow” or handle the potential error).(Citation: hasherezade debug)(Citation: AlKhaser Debug)(Citation: vxunderground debug) Malware may also leverage Structured Exception Handling (SEH) to detect debuggers by throwing an exception and detecting whether the process is suspended. SEH handles both hardware and software expectations, providing control over the exceptions including support for debugging. If a debugger is present, the program’s control will be transferred to the
Near-miss passage: T1087 Account Discovery. Tactics: discovery. Description: Adversaries may attempt to get a listing of valid accounts, usernames, or email addresses on a system or within a compromised environment. This information can help adversaries determine which accounts exist, which can aid in follow-on behavior such as brute-forcing, spear-phishing attacks, or account takeovers (e.g., [Valid Accounts](https://attack.mitre.org/techniques/T1078)). Adversaries may use several methods to enumerate accounts, including abuse of existing tools, built-in commands, and potential misconfigurations that leak account names and roles or permissions in the targeted environment. For examples, cloud environments typically provide easily accessible interfaces to obtain user lists.(Citation: AWS List Users)(Citation: Google Cloud - IAM Servie Accounts List API) On hosts, adversaries can use default [PowerShell](https://attack.mitre.org/techniques/T1059/001) and other command line functionality to identify accounts. Information about email addresses and accounts may also be extracted by searching an infected system’s files.