基于Rootkit隐藏行为特征的Linux恶意代码取证方法

doi:10.3969/j.issn.1671-1122.2020.11.005

摘要/Abstract

摘要：

近年来,在互联网不断发展的同时,网络安全问题也层出不穷,而在对抗网络安全威胁时,取证问题一直是个难题。尤其是针对Linux平台,目前主流的Linux开源取证工具多数存在滞后、效率低、无法对隐蔽性强的木马进行取证等问题。在Linux取证研究中,Rootkit木马具有隐蔽性强、危害性大的特点,传统检测方法难以进行有效检测。为解决上述问题,文章从Rootkit的行为和实现技术出发,对其启动机制和内存驻留机制进行研究分析,提炼恶意代码行为作为检测特征,提出一种基于Rootkit隐藏行为特征的Linux恶意代码取证方法。实验表明,文章提出的取证方法对各类Linux恶意代码具有很好的检出效果和取证效果,相较传统取证方法在检测效果上具有明显优势。

关键词: 计算机取证, Rootkit, 恶意代码, Linux系统

Abstract:

In recent years, with the continuous development of the Internet, network security problems emerge endlessly. When fighting against network security threats, forensics has always been a big problem. Especially for Linux platform, most mainstream Linux open source forensics tools are currently lagging behind, inefficient and unable to obtain evidence from the hidden Trojans. In the research of Linux forensics, because the Rootkit Trojan has the characteristics of strong concealment and great harm, traditional detection methods are difficult to carry out effective detection. In order to solve the above problems, starting from the behavior and implementation technology of Rootkit, this paper studies and analyzes its startup mechanism and memory resident mechanism, extracts malicious code behaviors as detection features, and proposes a Linux malicious code forensics method based on Rootkit hidden behavior characteristics. The experimental results show that the forensics method proposed in this paper has a good detection effect and forensics effect for various types of Linux malicious code, and has obvious advantages in detection effect compared with traditional forensics methods.

Key words: computer forensics, Rootkit, malicious code, Linux system

中图分类号:

TP309

文伟平, 陈夏润, 杨法偿. 基于Rootkit隐藏行为特征的Linux恶意代码取证方法[J]. 信息网络安全, 2020, 20(11): 32-42.

WEN Weiping, CHEN Xiarun, YANG Fachang. Malicious Code Forensics Method Based on Hidden Behavior Characteristics of Rootkit on Linux[J]. Netinfo Security, 2020, 20(11): 32-42.

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木马名称	木马简介
Remaiten	拥有扫描器、下载器和后门功能,目的在于入侵和控制一些运行的Linux系统目标,部署僵尸网络
Billgates	近年来较活跃的DDoS僵尸网络木马,通过部署木马所控制的傀儡机壮大僵尸网络
Reptile	Github上的LKM Rootkit,经常被黑客使用进行Rootkit隐藏
WNPS	Adore-ng木马的加强版,使用加密通信,在Linux 2.6.x内核中通用,隐蔽性很高
Ddrk	结合shv木马和adore-ng木马的特点、内核级别的Rootkit木马

木马名称	用户层检测结果	内核层检测结果	流量分析	是否检出木马
Remaiten	隐藏文件	无检测结果	恶意域名	是
Billgates	隐藏进程、隐藏文件、隐藏网络连接	隐藏进程、隐藏文件、隐藏网络连接	恶意IP	是
Reptile	隐藏端口	隐藏文件、隐藏网络连接、隐藏内核模块	无检测结果	是
WNPS	无检测结果	隐藏文件、隐藏进程、隐藏内核模块、关键数据结构篡改	无检测结果	是
Ddrk	隐藏进程	隐藏网络连接、隐藏进程、隐藏文件、关键数据结构篡改	无检测结果	是
Unknow1	隐藏端口	隐藏网络连接、隐藏文件、隐藏内核模块	恶意域名	是
Unknow2	无检测结果	隐藏内核模块、隐藏进程、关键数据结构篡改	无检测结果	是

木马取证工具	Remaiten	Billgates	Reptile	WNPS	Ddrk	Unknow1	Unknow2
Rkhunter	√	√	?	√	√	?	?
ChkRootkit	√	√	√	√	?	?	?
本文方法	√	√	√	√	√	√	√