Helminth

Helminth is a backdoor that has at least two variants - one written in VBScript and PowerShell that is delivered via a macros in Excel spreadsheets, and one that is a standalone Windows executable. [1]

ID: S0170
Type: MALWARE
Platforms: Windows
Contributors: Robert Falcone
Version: 1.2
Created: 16 January 2018
Last Modified: 11 April 2024

Techniques Used

Domain ID Name Use
Enterprise T1115 剪贴板数据

The executable version of Helminth has a module to log clipboard contents.[1]

Enterprise T1573 .001 加密通道: Symmetric Cryptography

Helminth encrypts data sent to its C2 server over HTTP with RC4.[1]

Enterprise T1547 .001 启动或登录自动启动执行: Registry Run Keys / Startup Folder

Helminth establishes persistence by creating a shortcut in the Start Menu folder.[1]

.009 启动或登录自动启动执行: Shortcut Modification

Helminth establishes persistence by creating a shortcut.[1]

Enterprise T1059 .001 命令与脚本解释器: PowerShell

One version of Helminth uses a PowerShell script.[1]

.003 命令与脚本解释器: Windows Command Shell

Helminth can provide a remote shell. One version of Helminth uses batch scripting.[1]

.005 命令与脚本解释器: Visual Basic

One version of Helminth consists of VBScript scripts.[1]

Enterprise T1071 .001 应用层协议: Web Protocols

Helminth can use HTTP for C2.[1]

.004 应用层协议: DNS

Helminth can use DNS for C2.[1]

Enterprise T1030 数据传输大小限制

Helminth splits data into chunks up to 23 bytes and sends the data in DNS queries to its C2 server.[1]

Enterprise T1074 .001 数据分段: Local Data Staging

Helminth creates folders to store output from batch scripts prior to sending the information to its C2 server.[1]

Enterprise T1132 .001 数据编码: Standard Encoding

For C2 over HTTP, Helminth encodes data with base64 and sends it via the "Cookie" field of HTTP requests. For C2 over DNS, Helminth converts ASCII characters into their hexadecimal values and sends the data in cleartext.[1]

Enterprise T1069 .001 权限组发现: Local Groups

Helminth has checked the local administrators group.[2]

.002 权限组发现: Domain Groups

Helminth has checked for the domain admin group and Exchange Trusted Subsystem groups using the commands net group Exchange Trusted Subsystem /domain and net group domain admins /domain.[2]

Enterprise T1027 .013 混淆文件或信息: Encrypted/Encoded File

The Helminth config file is encrypted with RC4.[1]

Enterprise T1119 自动化收集

A Helminth VBScript receives a batch script to execute a set of commands in a command prompt.[1]

Enterprise T1105 输入工具传输

Helminth can download additional files.[1]

Enterprise T1056 .001 输入捕获: Keylogging

The executable version of Helminth has a module to log keystrokes.[1]

Enterprise T1057 进程发现

Helminth has used Tasklist to get information on processes.[2]

Enterprise T1053 .005 预定任务/作业: Scheduled Task

Helminth has used a scheduled task for persistence.[3]

Enterprise T1553 .002 颠覆信任控制: Code Signing

Helminth samples have been signed with legitimate, compromised code signing certificates owned by software company AI Squared.[3]

Groups That Use This Software

ID Name References
G0049 OilRig

[1][4][5]

References