This rule detects the presence of the SoftWrap YARA signature, which typically identifies specific malware families or obfuscated payloads that adversaries use to establish a foothold or execute malicious code. Proactively hunting for this indicator in Azure Sentinel allows the SOC team to identify compromised endpoints or suspicious files before they progress to lateral movement or data exfiltration, reducing the overall dwell time of the threat.
rule SoftWrap
{
meta:
author="malware-lu"
strings:
$a0 = { 52 53 51 56 57 55 E8 [4] 5D 81 ED 36 [3] E8 ?? 01 [2] 60 BA [4] E8 [4] 5F }
condition:
$a0 at pe.entry_point
}This YARA rule can be deployed in the following contexts:
This rule contains 1 string patterns in its detection logic.
Scenario: A developer or system administrator uses a text editor (e.g., VS Code, Notepad++, Sublime Text) with the “Soft Wrap” feature enabled to review large log files or source code. The YARA rule may match the specific string or memory pattern associated with the editor’s internal buffer handling when soft-wrapping is active, rather than the malicious payload itself.
Code.exe, notepad.exe, sublime_text.exe) and the file path contains typical editor configuration or cache directories (e.g., %APPDATA%\Code, %LOCALAPPDATA%\Sublime Text).Scenario: A scheduled maintenance job runs a custom PowerShell or Python script that processes large CSV or JSON files. If the script uses a library that implements soft-wrapping for console output or log formatting (e.g., rich in Python, or specific .NET string formatting), the memory footprint may match the YARA signature.
--format, --wrap, or --log-level, and the process name matches common scripting hosts (python.exe, pwsh.exe, node.exe) while the working directory is within a known application or maintenance folder (e.g., C:\Scripts\Maintenance, C:\App\Logs).Scenario: A GUI application (e.g., a CRM, ERP, or monitoring dashboard like Splunk, Grafana, or ServiceNow client) renders long text fields in a table or log viewer. These applications often use internal UI frameworks that apply soft-wrapping to text elements, potentially triggering the YARA rule if it inspects UI memory structures or specific string constants.