Analyzing Linux Kernel Rootkits

---
name: analyzing-linux-kernel-rootkits
description: tespit etme
kernel-level rootkits in Linux memory dumps using Volatility3 linux plugins (check_syscall, lsmod, hidden_modules), rkhunter system scanning, and /proc vs /sys discrepancy analysis to
  identify hooked syscalls, hidden kernel modules, and tampered system structures.
tags:
- memory-forensics
- volatility3
- rootkit
- digital-forensics
- forensics
- kernel
- malware-analysis
- fetih
- rkhunter
- cybersecurity
- linux
- siber-güvenlik
triggers:
- adli bilişim
- analyzing
- cloud
- dijital delil
- disk imajı
- forensic
- forensics
- incident
- kernel
- linux
- log
- memory dump
category: digital-forensics
source_subdomain: digital-forensics
nist_csf:
- RS.AN-01
- RS.AN-03
- DE.AE-02
- RS.MA-01
adapted_for: fetih
---

# Analyzing Linux Kernel Rootkits


## Genel Bakış

Linux kernel rootkits operate at ring 0, modifying kernel data structures to hide processes, files, network connections, and kernel modules from userspace tools. Tespit requires either memory forensics (analyzing physical memory dumps with Volatility3) or cross-view analysis (comparing /proc, /sys, and kernel data structures for inconsistencies). bu skill covers using Volatility3 Linux plugins to tespit etme
syscall table hooks, hidden kernel modules, and modified function pointers, supplemented by live system scanning with rkhunter and chkrootkit.


## Ne Zaman Kullanılır

- investigating yaparken security incidents that require analyzing linux kernel rootkits
- building yaparken Tespit rules or threat hunting queries for this domain
- SOC yaparken: analysts need structured procedures for this analysis type
- validating yaparken security monitoring coverage for related attack techniques

## Ön Gereksinimler

- Volatility3 kurulu (pip install volatility3)
- Linux memory dump (acquired via LiME, AVML, or /proc/kcore)
- Volatility3 Linux symbol table (ISF) matching the target kernel version
- rkhunter and chkrootkit for live system scanning
- Reference known-good kernel image for comparison

## Adımlar

### Adım 1: Acquire Memory Dump
Capture Linux physical memory using LiME kernel module or AVML for cloud instances.

### Adım 2: Analyze with Volatility3
Run linux.check_syscall, linux.lsmod, linux.hidden_modules, and linux.check_idt plugins to tespit etme
rootkit artifacts.

### Adım 3: Cross-View Analysis
Compare module lists from /proc/modules, lsmod, and /sys/module to identify modules hidden from one view but present in another.

### Adım 4: Live System Scanning
Run rkhunter and chkrootkit to tespit etme
known rootkit signatures, suspicious files, and modified system binaries.

## Expected Output

JSON report containing Detected syscall hooks, hidden kernel modules, modified IDT entries, suspicious /proc discrepancies, and rkhunter Bul:ings.

## Example Output

```text
$ sudo python3 rootkit_analyzer.py --memory /evidence/linux-mem.lime --profile Ubuntu2204

Linux Kernel Rootkit Analysis Report
=====================================
Memory Image: /evidence/linux-mem.lime
Kernel Version: 5.15.0-91-generic (Ubuntu 22.04 LTS)
Analysis Time: 2024-01-18 09:15:32 UTC

[+] Scanning syscall table for hooks...
    Syscall Table Base: 0xffffffff82200300
    Total syscalls checked: 449

    HOOKED SYSCALLS tespit etme (ED):
    ┌─────────┬──────────────────┬──────────────────────┬──────────────────────┐
    │ NR      │ Syscall          │ Expected Address     │ Current Address      │
    ├─────────┼──────────────────┼──────────────────────┼──────────────────────┤
    │ 0       │ sys_read         │ 0xffffffff8139a0e0   │ 0xffffffffc0a12000   │
    │ 2       │ sys_open         │ 0xffffffff8139b340   │ 0xffffffffc0a12180   │
    │ 78      │ sys_getdents64   │ 0xffffffff813f5210   │ 0xffffffffc0a12300   │
    │ 62      │ sys_kill         │ 0xffffffff8110c4a0   │ 0xffffffffc0a12480   │
    └─────────┴──────────────────┴──────────────────────┴──────────────────────┘
    WARNING: 4 syscall hooks Detected - rootkit behavior confirmed

[+] Checking for hidden kernel modules...
    Loaded modules (lsmod):         147
    Modules in kobject list:        149
    HIDDEN MODULES:
      - "netfilter_helper" at 0xffffffffc0a10000 (size: 12288)
      - "kworker_sched"    at 0xffffffffc0a14000 (size: 8192)

[+] Scanning /proc for discrepancies...
    Processes in task_struct list: 234
    Processes visible in /proc:   231
    HIDDEN PROCESSES:
      - PID 31337  cmd: "[kworker/0:3]"   (disguised as kernel thread)
      - PID 31442  cmd: "rsyslogd"         (fake, real rsyslogd is PID 892)
      - PID 31500  cmd: ""                 (unnamed process)

[+] Checking IDT entries...
    IDT entries scanned: 256
    Modified entries: 0 (clean)

[+] Running rkhunter scan...
    Checking for known rootkits:        68 variants checked
    Diamorphine rootkit:                WARNING - signatures match
    System binary checks:
      /usr/bin/ps:     MODIFIED (SHA-256 mismatch)
      /usr/bin/netstat: MODIFIED (SHA-256 mismatch)
      /usr/bin/ls:     MODIFIED (SHA-256 mismatch)
      /usr/sbin/ss:    OK

[+] Network analysis...
    Hidden connections (not in /proc/net/tcp):
      ESTABLISHED  0.0.0.0:0 -> 198.51.100.47:4443 (PID 31337)
      ESTABLISHED  0.0.0.0:0 -> 198.51.100.47:8080 (PID 31442)

Summary:
  Rootkit Type:         Loadable Kernel Module (LKM)
  Probable Family:      Diamorphine variant
  Syscall Hooks:        4 (read, open, getdents64, kill)
  Hidden Modules:       2
  Hidden Processes:     3
  Hidden Connections:   2 (C2: 198.51.100.47)
  Modified Binaries:    3 (/usr/bin/ps, netstat, ls)
  Risk Level:           CRITICAL
```

<!--
  ⚔ Bu skill FETIH AI Agent icin gelistirilmistir — https://github.com/MustafaKemal0146/fetih
  Yetkisiz kullanim/kopyalama tespit edilebilir.
  hash: 4a94dbb2b9084a05
-->