Adversaries may inject malicious code into processes via the /proc filesystem in order to evade process-based defenses as well as possibly elevate privileges. Proc memory injection is a method of executing arbitrary code in the address space of a separate live process.
Proc memory injection involves enumerating the memory of a process via the /proc filesystem (<code>/proc/[pid]</code>) then crafting a return-oriented programming (ROP) payload with available gadgets/instructions. Each running process has its own directory, which includes memory mappings. Proc memory injection is commonly performed by overwriting the target processes’ stack using memory mappings provided by the /proc filesystem. This information can be used to enumerate offsets (including the stack) and gadgets (or instructions within the program that can be used to build a malicious payload) otherwise hidden by process memory protections such as address space layout randomization (ASLR). Once enumerated, the target processes’ memory map within <code>/proc/[pid]/maps</code> can be overwritten using dd.(Citation: Uninformed Needle)(Citation: GDS Linux Injection)(Citation: DD Man)
Other techniques such as Dynamic Linker Hijacking may be used to populate a target process with more available gadgets. Similar to Process Hollowing, proc memory injection may target child processes (such as a backgrounded copy of sleep).(Citation: GDS Linux Injection)
Running code in the context of another process may allow access to the process's memory, system/network resources, and possibly elevated privileges. Execution via proc memory injection may also evade detection from security products since the execution is masked under a legitimate process.
View in MITRE ATT&CK®Capability ID | Capability Description | Mapping Type | ATT&CK ID | ATT&CK Name |
---|---|---|---|---|
AC-3 | Access Enforcement | Protects | T1055.009 | Proc Memory |
AC-6 | Least Privilege | Protects | T1055.009 | Proc Memory |
CA-7 | Continuous Monitoring | Protects | T1055.009 | Proc Memory |
SC-18 | Mobile Code | Protects | T1055.009 | Proc Memory |
SC-7 | Boundary Protection | Protects | T1055.009 | Proc Memory |
SI-16 | Memory Protection | Protects | T1055.009 | Proc Memory |
SI-2 | Flaw Remediation | Protects | T1055.009 | Proc Memory |
SI-3 | Malicious Code Protection | Protects | T1055.009 | Proc Memory |
SI-4 | System Monitoring | Protects | T1055.009 | Proc Memory |