归档收集数据是攻击者在渗透过程中对窃取信息进行压缩加密处理的技术,旨在降低数据泄露风险并规避检测。攻击者通常使用系统自带工具(如tar、zip)或第三方库对数据进行归档处理,防御方可通过对压缩工具进程的监控、异常命令行参数检测,以及网络流量中加密文件特征的识别来进行防护。现有检测手段主要依赖文件头特征分析、熵值检测和传输行为异常识别等技术。
为应对传统检测方法,攻击者发展出融合密码学、隐写术与协议仿真的新型归档技术,通过多模态隐匿手段突破基于单一特征检测的防御体系。这些技术将数据隐匿过程解构为格式伪装、时空分散、信息隐藏等多个维度,形成具有自适应能力的动态匿迹系统。
当前归档数据匿迹技术的核心演进方向是构建多维融合的隐匿生态。多层嵌套压缩加密通过算法组合复杂度对抗密码分析,隐写式封装实现数据在载体文件中的不可见存储,分片归档利用传输协议的异构性稀释特征浓度,格式伪装则突破人工审计与自动化检测的协同防御。这些技术的共性在于:①采用纵深加密体系增加数据恢复难度;②利用合法业务流量特征构建传输掩护;③引入环境感知机制动态调整隐匿策略。例如分片传输技术结合时间延迟与协议跳变,使防御方难以建立有效的流量关联分析;格式伪装技术通过深度仿真常见文档结构,将恶意归档文件融入日常文件交换场景。
匿迹技术的发展导致传统基于文件特征识别的检测方法逐渐失效,防御方需构建多维特征融合分析模型,结合数据流时空关联分析、隐写检测算法增强,以及行为链溯源能力,建立覆盖数据预处理、传输、重组全周期的防护体系。
| 效应类型 | 是否存在 |
|---|---|
| 特征伪装 | ✅ |
| 行为透明 | ❌ |
| 数据遮蔽 | ✅ |
| 时空释痕 | ✅ |
攻击者通过精确仿冒合法文件格式的头部结构、元数据特征,使加密压缩数据呈现为正常文档或系统文件。例如将窃密数据封装成具有标准DOCX文件结构的文档,在文件资源管理器中显示合规图标与预览内容。这种深度伪装使防御方难以通过表面特征识别异常文件。
采用多层加密算法(如AES+RSA混合加密)对归档数据进行端到端加密,结合压缩改变数据熵值分布。加密过程在内存中完成且不遗留临时文件,确保从存储到传输的全链路数据不可读性,有效规避内容检测。
通过分片传输机制将完整数据包拆解为多个微片段,经由不同时间窗口和网络通道分别传输。这种时空分离策略稀释了数据泄露的集中特征,使得传统基于单次大文件传输的检测模型失效,防御方难以通过局部流量捕获发现完整攻击链。
| ID | Name | Description |
|---|---|---|
| S0045 | ADVSTORESHELL |
ADVSTORESHELL encrypts with the 3DES algorithm and a hardcoded key prior to exfiltration.[1] |
| S0331 | Agent Tesla |
Agent Tesla can encrypt data with 3DES before sending it over to a C2 server.[2] |
| S0622 | AppleSeed |
AppleSeed has compressed collected data before exfiltration.[3] |
| G0007 | APT28 |
APT28 used a publicly available tool to gather and compress multiple documents on the DCCC and DNC networks.[4] |
| G0050 | APT32 |
APT32's backdoor has used LZMA compression and RC4 encryption before exfiltration.[5] |
| S0456 | Aria-body |
Aria-body has used ZIP to compress data gathered on a compromised host.[6] |
| G0001 | Axiom |
Axiom has compressed and encrypted data prior to exfiltration.[7] |
| S0093 | Backdoor.Oldrea |
Backdoor.Oldrea writes collected data to a temporary file in an encrypted form before exfiltration to a C2 server.[8] |
| S0521 | BloodHound |
BloodHound can compress data collected by its SharpHound ingestor into a ZIP file to be written to disk.[9][10] |
| S0657 | BLUELIGHT | |
| S1039 | Bumblebee |
Bumblebee can compress data stolen from the Registry and volume shadow copies prior to exfiltration.[12] |
| S0454 | Cadelspy |
Cadelspy has the ability to compress stolen data into a .cab file.[13] |
| S0667 | Chrommme |
Chrommme can encrypt and store on disk collected data before exfiltration.[14] |
| S0187 | Daserf |
Daserf hides collected data in password-protected .rar archives.[15] |
| G0035 | Dragonfly |
Dragonfly has compressed data into .zip files prior to exfiltration.[16] |
| S0567 | Dtrack |
Dtrack packs collected data into a password protected archive.[17] |
| G1003 | Ember Bear |
Ember Bear has compressed collected data prior to exfiltration.[18] |
| S0363 | Empire | |
| S0091 | Epic |
Epic encrypts collected data using a public key framework before sending it over the C2 channel.[20] Some variants encrypt the collected data with AES and encode it with base64 before transmitting it to the C2 server.[21] |
| S0343 | Exaramel for Windows |
Exaramel for Windows automatically encrypts files before sending them to the C2 server.[22] |
| S0267 | FELIXROOT |
FELIXROOT encrypts collected data with AES and Base64 and then sends it to the C2 server.[23] |
| G0037 | FIN6 |
Following data collection, FIN6 has compressed log files into a ZIP archive prior to staging and exfiltration.[24] |
| S0249 | Gold Dragon |
Gold Dragon encrypts data using Base64 before being sent to the command and control server.[25] |
| G0004 | Ke3chang |
The Ke3chang group has been known to compress data before exfiltration.[26] |
| S0487 | Kessel |
Kessel can RC4-encrypt credentials before sending to the C2.[27] |
| S0356 | KONNI |
KONNI has encrypted data and files prior to exfiltration.[28] |
| G0032 | Lazarus Group |
Lazarus Group has compressed exfiltrated data with RAR and used RomeoDelta malware to archive specified directories in .zip format, encrypt the .zip file, and upload it to C2. [29][30][31] |
| G0065 | Leviathan |
Leviathan has archived victim's data prior to exfiltration.[32] |
| S0395 | LightNeuron |
LightNeuron contains a function to encrypt and store emails that it collects.[33] |
| S0681 | Lizar |
Lizar has encrypted data before sending it to the server.[34] |
| S1101 | LoFiSe |
LoFiSe can collect files into password-protected ZIP-archives for exfiltration.[35] |
| G1014 | LuminousMoth |
LuminousMoth has manually archived stolen files from victim machines before exfiltration.[36] |
| S0010 | Lurid | |
| S0409 | Machete |
Machete stores zipped files with profile data from installed web browsers.[38] |
| G0045 | menuPass |
menuPass has encrypted files and information before exfiltration.[39][40] |
| S0198 | NETWIRE |
NETWIRE has the ability to compress archived screenshots.[41] |
| G0040 | Patchwork |
Patchwork encrypted the collected files' path with AES and then encoded them with base64.[42] |
| S0517 | Pillowmint |
Pillowmint has encrypted stolen credit card information with AES and further encoded it with Base64.[43] |
| S1012 | PowerLess |
PowerLess can encrypt browser database files prior to exfiltration.[44] |
| S0113 | Prikormka |
After collecting documents from removable media, Prikormka compresses the collected files, and encrypts it with Blowfish.[45] |
| S0279 | Proton | |
| S1148 | Raccoon Stealer |
Raccoon Stealer archives collected system information in a text f ile, |
| S0375 | Remexi |
Remexi encrypts and adds all gathered browser data into files for upload to C2.[48] |
| S0253 | RunningRAT |
RunningRAT contains code to compress files.[25] |
| S0445 | ShimRatReporter |
ShimRatReporter used LZ compression to compress initial reconnaissance reports before sending to the C2.[49] |
| S1140 | Spica | |
| S0586 | TAINTEDSCRIBE |
TAINTEDSCRIBE has used |
| S0257 | VERMIN | |
| S0515 | WellMail | |
| S0658 | XCSSET |
XCSSET will compress entire |
| S0251 | Zebrocy |
Zebrocy has used a method similar to RC4 as well as AES for encryption and hexadecimal for encoding data before exfiltration. [55][56][57] |
| ID | Mitigation | Description |
|---|---|---|
| M1047 | Audit |
System scans can be performed to identify unauthorized archival utilities. |
| ID | Data Source | Data Component | Detects |
|---|---|---|---|
| DS0017 | Command | Command Execution |
Monitor executed commands and arguments for actions that will aid in compression or encrypting data that is collected prior to exfiltration, such as tar. |
| DS0022 | File | File Creation |
Monitor newly constructed files being written with extensions and/or headers associated with compressed or encrypted file types. Detection efforts may focus on follow-on exfiltration activity, where compressed or encrypted files can be detected in transit with a network intrusion detection or data loss prevention system analyzing file headers. |
| DS0009 | Process | Process Creation |
Monitor for newly constructed processes and/or command-lines that aid in compression or encrypting data that is collected prior to exfiltration, such as 7-Zip, WinRAR, and WinZip. |
| DS0012 | Script | Script Execution |
Monitor for any attempts to enable scripts running on a system would be considered suspicious. If scripts are not commonly used on a system, but enabled, scripts running out of cycle from patching or other administrator functions are suspicious. Scripts should be captured from the file system when possible to determine their actions and intent. |