Cross-source coverage
T1027.001 / ATT&CK
Obfuscated Files or Information: Binary Padding
10 rules across 3 sources.
From MITRE ATT&CK 19.2
Adversaries may use binary padding to add junk data and change the on-disk representation of malware. This can be done without affecting the functionality or behavior of a binary, but can increase the size of the binary beyond what some security tools are capable of handling due to file size limitations.
Binary padding effectively changes the checksum of the file and can also be used to avoid hash-based blocklists and static anti-virus signatures. The padding used is commonly generated by a function to create junk data and then appended to the end or applied to sections of malware. Increasing the file size may decrease the effectiveness of certain tools and detection capabilities that are not designed or configured to scan large files. This may also reduce the likelihood of being collected for analysis. Public file scanning services, such as VirusTotal, limits the maximum size of an uploaded file to be analyzed.
- Tactics
- Stealth
- Platforms
- Linux · macOS · Windows
- Telemetry
-
WinEventLog:SecurityWinEventLog:Sysmonauditd:SYSCALLlinux:osquerymacos:unifiedlogfs:fsusage
How MITRE says to detect it DET0553
Detection Strategy for Obfuscated Files or Information: Binary Padding
Windows Analytic 1528
Detects the creation or execution of padded binary files (e.g., large size but minimal legitimate content) followed by process execution or lateral movement from the host.
WinEventLog:SecurityEventCode=4688WinEventLog:SecurityEventCode=4663, 4670, 4656WinEventLog:SysmonEventCode=11
Linux Analytic 1529
Detects abnormal creation of binary files with significant size that are subsequently executed or accessed by non-standard users.
auditd:SYSCALLopenauditd:SYSCALLexecvelinux:osqueryfile_events
macOS Analytic 1530
Monitors for anomalous binary files written to disk with padded size and subsequent execution by user or service context.
macos:unifiedlogprocess:spawnfs:fsusagefile write
elastic/protections-artifacts
5 rules| Detection | Severity | Format |
|---|---|---|
| Oversized DLL Creation followed by SideLoad | Undefined | Elastic TOML |
| Potential Evasion via Oversized Image Load | Undefined | Elastic TOML |
| Rundll32 or Regsvr32 Executing an OverSized File | Undefined | Elastic TOML |
| Suspicious Execution from an Oversized Executable | Undefined | Elastic TOML |
| Suspicious Oversized Script Execution | Undefined | Elastic TOML |
SigmaHQ/sigma
3 rules| Detection | Severity | Format |
|---|---|---|
| Binary Padding - Linux | High | Sigma |
| Binary Padding - MacOS | High | Sigma |
| Failed Code Integrity Checks | Informational | Sigma |
socfortress/Wazuh-Rules
2 rules| Detection | Severity | Format |
|---|---|---|
| Binary padding detected via dd on evil-binary (Possible hash evasion) | Medium | Wazuh XML |
| Binary padding detected via truncate on evil-binary (Hash modification attempt) | Medium | Wazuh XML |