创建或修改系统进程

创建或修改系统进程是攻击者通过操作操作系统级服务、守护进程或代理程序实现持久化驻留和权限提升的关键技术。攻击者可能安装新服务或篡改现有服务配置,使其在系统启动时或定期执行恶意负载。传统防御主要依赖监控服务配置变更(如Windows注册表Services子键)、检测异常进程树结构、分析服务二进制文件特征,以及审查服务相关命令行调用日志等手段。

为规避传统检测机制,攻击者发展出高度隐蔽的进程操纵技术,通过内存化执行、动态伪装和深度寄生等手法,将恶意服务融入操作系统核心组件运行框架,构建难以通过常规手段识别的持久化攻击链。

当前系统进程匿迹技术的共性在于突破传统"文件-进程"对应关系,重构恶意服务的存储形态与运行模式:合法进程代码寄生注入技术消解了独立恶意进程的存在性,通过宿主进程的资源复用实现"零特征"驻留;动态服务配置伪装技术构建了服务元数据的动态混淆能力,使恶意服务在配置审计层面呈现合法特征;无文件化内存驻留服务技术则彻底摆脱磁盘存储依赖,在内存维度构建完整的服务运行生态。三类技术的核心创新均围绕"去实体化"与"环境拟态"展开,通过深度利用操作系统底层机制,使恶意服务在创建、加载、运行各阶段均符合系统合法性校验规则,同时规避基于特征匹配的静态检测。特别是内存级攻击技术的成熟,标志着系统进程对抗进入"无实体化"阶段,传统基于文件监控的防御体系面临根本性挑战。

匿迹技术的演进迫使防御体系向内存行为分析、运行时完整性校验等深度检测方向转型。需构建基于硬件虚拟化的内存监控能力,开发服务行为动态基线模型,并强化服务组件间的信任链验证机制,方能有效应对新型隐蔽进程威胁。

ID: T1543
Sub-techniques:  T1543.001, T1543.002, T1543.003
Platforms: Containers, Linux, Windows, macOS
Version: 1.2
Created: 10 January 2020
Last Modified: 15 February 2024

匿迹效应

效应类型 是否存在
特征伪装
行为透明
数据遮蔽
时空释痕

特征伪装

攻击者通过深度仿冒合法服务特征实现伪装,包括动态生成符合目标环境命名规范的服务名称、伪造数字签名信息、复用系统核心进程资源等。例如将恶意服务配置信息与系统原生服务采用相同的描述模板,使得服务枚举工具无法通过文本特征识别异常,实现攻击载荷的"白名单化"隐匿。

数据遮蔽

在无文件化内存驻留技术中,恶意服务的配置数据和执行代码完全存储于加密内存区域,采用反内存转储技术阻止关键数据提取。部分高级实现会通过TLS加密通道传输配置信息,或使用即时编译(JIT)技术动态生成执行代码,使得传统基于磁盘取证或内存特征扫描的检测手段失效。

时空释痕

攻击者采用低频触发和条件激活机制,使恶意服务仅在特定系统事件(如网络断开、屏保启动)或时间窗口(如每月首个工作日)执行攻击载荷。通过将恶意行为分散在长周期内,并关联正常系统活动节奏,显著降低单位时间内的可检测特征浓度,规避基于行为频率的异常检测模型。

Procedure Examples

ID Name Description
S0401 Exaramel for Linux

Exaramel for Linux has a hardcoded location that it uses to achieve persistence if the startup system is Upstart or System V and it is running as root.[1]

S1152 IMAPLoader

IMAPLoader modifies Windows tasks on the victim machine to reference a retrieved PE file through a path modification.[2]

S1121 LITTLELAMB.WOOLTEA

LITTLELAMB.WOOLTEA can initialize itself as a daemon to run persistently in the background.[3]

S1142 LunarMail

LunarMail can create an arbitrary process with a specified command line and redirect its output to a staging directory.[4]

Mitigations

ID Mitigation Description
M1047 Audit

Use auditing tools capable of detecting privilege and service abuse opportunities on systems within an enterprise and correct them.

M1040 Behavior Prevention on Endpoint

On Windows 10, enable Attack Surface Reduction (ASR) rules to prevent an application from writing a signed vulnerable driver to the system.[5] On Windows 10 and 11, enable Microsoft Vulnerable Driver Blocklist to assist in hardening against third party-developed drivers.[6]

M1045 Code Signing

Enforce registration and execution of only legitimately signed service drivers where possible.

M1033 Limit Software Installation

Restrict software installation to trusted repositories only and be cautious of orphaned software packages.

M1028 Operating System Configuration

Ensure that Driver Signature Enforcement is enabled to restrict unsigned drivers from being installed.

M1026 Privileged Account Management

Manage the creation, modification, use, and permissions associated to privileged accounts, including SYSTEM and root.

M1022 Restrict File and Directory Permissions

Restrict read/write access to system-level process files to only select privileged users who have a legitimate need to manage system services.

M1054 Software Configuration

Where possible, consider enforcing the use of container services in rootless mode to limit the possibility of privilege escalation or malicious effects on the host running the container.

M1018 User Account Management

Limit privileges of user accounts and groups so that only authorized administrators can interact with system-level process changes and service configurations.

Detection

ID Data Source Data Component Detects
DS0017 Command Command Execution

Command-line invocation of tools capable of modifying services may be unusual, depending on how systems are typically used in a particular environment. Look for abnormal process call trees from known services and for execution of other commands that could relate to Discovery or other adversary techniques.

DS0032 Container Container Creation

Monitor for newly constructed containers that repeatedly execute malicious payloads as part of persistence or privilege escalation.

DS0027 Driver Driver Load

Monitor for new service driver installations and loads (ex: Sysmon Event ID 6) that are not part of known software update/patch cycles.

DS0022 File File Creation

Monitor for newly constructed files that may create or modify system-level processes to repeatedly execute malicious payloads as part of persistence.

File Modification

Monitor for changes to files associated with system-level processes.

DS0009 Process OS API Execution

Monitor for API calls that may create or modify system-level processes to repeatedly execute malicious payloads as part of persistence.

Process Creation

New, benign system processes may be created during installation of new software.

DS0019 Service Service Creation

Monitor for newly constructed services/daemons that may create or modify system-level processes to repeatedly execute malicious payloads as part of persistence.

Service Modification

Monitor for changes to system processes that do not correlate with known software, patch cycles, etc., including by comparing results against a trusted system baseline.

DS0024 Windows Registry Windows Registry Key Creation

Monitor for newly constructed windows registry keys that may create or modify system-level processes to repeatedly execute malicious payloads as part of persistence.

Windows Registry Key Modification

Monitor for changes to windows registry keys and/or values that may create or modify system-level processes to repeatedly execute malicious payloads as part of persistence.

References