Detect VDSO Hijacking in IBM QRadar
Adversaries may inject malicious code into processes via VDSO hijacking in order to evade process-based defenses as well as possibly elevate privileges. Virtual dynamic shared object (vdso) hijacking is a method of executing arbitrary code in the address space of a separate live process. VDSO hijacking involves redirecting calls to dynamically linked shared libraries. Memory protections may prevent writing executable code to a process via Ptrace System Calls. However, an adversary may hijack the syscall interface code stubs mapped into a process from the vdso shared object to execute syscalls to open and map a malicious shared object. This code can then be invoked by redirecting the execution flow of the process via patched memory address references stored in a process' global offset table (which store absolute addresses of mapped library functions).
MITRE ATT&CK
- Technique
- T1055 Process Injection
- Sub-technique
- T1055.014 VDSO Hijacking
- Canonical reference
- https://attack.mitre.org/techniques/T1055/014/
QRadar Detection Query
SELECT
DATEFORMAT(devicetime, 'yyyy-MM-dd HH:mm:ss') AS event_time,
sourceip,
hostname,
username,
QIDNAME(qid) AS event_name,
"payload",
LOGSOURCENAME(logsourceid) AS log_source
FROM events
WHERE
logsourcetypeid = 105
AND LOGSOURCENAME(logsourceid) LIKE '%auditd%'
AND devicetime > (NOW() - 86400000)
AND (
(
payload ILIKE '%syscall%'
AND (
payload ILIKE '%ptrace%'
OR payload ILIKE '%mprotect%'
OR payload ILIKE '%mmap%'
)
AND (
payload ILIKE '%vdso%'
OR payload ILIKE '%linux-gate%'
OR payload ILIKE '%linux-vdso%'
OR payload ILIKE '%PROT_EXEC%'
OR payload ILIKE '%0x5 %'
OR payload ILIKE '%0x7 %'
)
)
OR (
payload ILIKE '%ptrace%'
AND (
payload ILIKE '% a0=1 %'
OR payload ILIKE '% a0=2 %'
OR payload ILIKE '% a0=4 %'
OR payload ILIKE '% a0=5 %'
)
)
)
AND payload NOT ILIKE '%exe="/usr/bin/gdb"%'
AND payload NOT ILIKE '%exe="/usr/bin/strace"%'
AND payload NOT ILIKE '%exe="/usr/bin/ltrace"%'
AND payload NOT ILIKE '%exe="/usr/bin/valgrind"%'
AND payload NOT ILIKE '%exe="/usr/bin/java"%'
AND payload NOT ILIKE '%ld-linux%'
AND payload NOT ILIKE '%libc%'
ORDER BY devicetime DESC
LIMIT 1000Detects VDSO hijacking indicators by querying Linux auditd log sources in QRadar for suspicious ptrace PEEK/POKE syscalls targeting the vdso memory region and mprotect/mmap calls with executable permission flags, filtering out known legitimate debuggers and system libraries.
Data Sources
Required Tables
False Positives & Tuning
- Security scanning tools and endpoint agents that perform memory inspection may generate ptrace events matching this pattern during regular scans
- Containerized JVM-based applications frequently use mprotect with PROT_EXEC for JIT code regions; container runtime processes may appear suspicious without context
- Custom application loaders and plugin frameworks that use dlopen/dlmopen at runtime can trigger mmap with executable flags when loading shared objects dynamically
Other platforms for T1055.014
Testing Methodology
Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Inspect VDSO Memory Region
Expected signal: auditd: open() on /proc/<pid>/maps. The VDSO mapping shows the address range of the vdso in the target process.
- Test 2Check GOT Entries of Running Process
Expected signal: auditd: readlink and open on /proc/<pid>/exe, execution of readelf. No direct security events from GOT inspection — this is a defensive analysis technique.
- Test 3mprotect Executable Permission Change Detection
Expected signal: Syslog: python3 process execution. No actual mprotect call with PROT_EXEC in this safe test. In a real attack: auditd SYSCALL record with syscall=10 (mprotect) and a2 containing PROT_EXEC flag.
References (5)
- https://attack.mitre.org/techniques/T1055/014/
- https://web.archive.org/web/20210205211142/https://backtrace.io/blog/backtrace/elf-shared-library-injection-forensics/
- https://web.archive.org/web/20150711051625/http://vxer.org/lib/vrn00.html
- https://lwn.net/Articles/604515/
- https://web.archive.org/web/20051013084246/http://www.trilithium.com/johan/2005/08/linux-gate/
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