RedCurl

RedCurl is a threat actor active since 2018 notable for corporate espionage targeting a variety of locations, including Ukraine, Canada and the United Kingdom, and a variety of industries, including but not limited to travel agencies, insurance companies, and banks.[1] RedCurl is allegedly a Russian-speaking threat actor.[1][2] The group’s operations typically start with spearphishing emails to gain initial access, then the group executes discovery and collection commands and scripts to find corporate data. The group concludes operations by exfiltrating files to the C2 servers.

ID: G1039
Contributors: Joe Gumke, U.S. Bank
Version: 1.0
Created: 23 September 2024
Last Modified: 23 September 2024

Techniques Used

Domain ID Name Use
Enterprise T1555 .003 从密码存储中获取凭证: Credentials from Web Browsers

RedCurl used LaZagne to obtain passwords from web browsers.[1][2]

Enterprise T1005 从本地系统获取数据

RedCurl has collected data from the local disk of compromised hosts.[1][2]

Enterprise T1039 从网络共享驱动器获取数据

RedCurl has collected data about network drives.[1][2]

Enterprise T1537 传输数据至云账户

RedCurl has used cloud storage to exfiltrate data, in particular the megatools utilities were used to exfiltrate data to Mega, a file storage service.[1][2]

Enterprise T1036 .005 伪装: Match Legitimate Name or Location

RedCurl mimicked legitimate file names and scheduled tasks, e.g. MicrosoftCurrentupdatesCheck andMdMMaintenenceTask to mask malicious files and scheduled tasks.[1][2]

Enterprise T1199 信任关系

RedCurl has gained access to a contractor to pivot to the victim’s infrastructure.[3]

Enterprise T1573 .001 加密通道: Symmetric Cryptography

RedCurl has used AES-128 CBC to encrypt C2 communications.[2]

.002 加密通道: Asymmetric Cryptography

RedCurl has used HTTPS for C2 communication.[1][2]

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

RedCurl has established persistence by creating entries in HKCU\Software\Microsoft\Windows\CurrentVersion\Run.[1][2]

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

RedCurl has used PowerShell to execute commands and to download malware.[1][2][4]

.003 命令与脚本解释器: Windows Command Shell

RedCurl has used the Windows Command Prompt to execute commands.[1][2][4]

.005 命令与脚本解释器: Visual Basic

RedCurl has used VBScript to run malicious files.[1][2]

.006 命令与脚本解释器: Python

RedCurl has used a Python script to establish outbound communication and to execute commands using SMB port 445.[4]

Enterprise T1071 .001 应用层协议: Web Protocols

RedCurl has used HTTP, HTTPS and Webdav protocls for C2 communications.[1][2]

Enterprise T1587 .001 开发能力: Malware

RedCurl has created its own tools to use during operations.[3]

Enterprise T1560 .001 归档收集数据: Archive via Utility

RedCurl has downloaded 7-Zip to decompress password protected archives.[4]

Enterprise T1003 .001 操作系统凭证转储: LSASS Memory

RedCurl used LaZagne to obtain passwords from memory.[1][2]

Enterprise T1083 文件和目录发现

RedCurl has searched for and collected files on local and network drives.[3][1][2]

Enterprise T1552 .001 未加密凭证: Credentials In Files

RedCurl used LaZagne to obtain passwords in files.[1][2]

.002 未加密凭证: Credentials in Registry

RedCurl used LaZagne to obtain passwords in the Registry.[1][2]

Enterprise T1080 污染共享内容

RedCurl has placed modified LNK files on network drives for lateral movement.[1][2]

Enterprise T1027 混淆文件或信息

RedCurl has used malware with string encryption.[3] RedCurl has also encrypted data and has encoded PowerShell commands using Base64.[1][2] RedCurl has used PyArmor to obfuscate code execution of LaZagne. [1] Additionally, RedCurl has obfuscated downloaded files by renaming them as commonly used tools and has used echo, instead of file names themselves, to execute files.[4]

Enterprise T1204 .001 用户执行: Malicious Link

RedCurl has used malicious links to infect the victim machines.[1][2]

.002 用户执行: Malicious File

RedCurl has used malicious files to infect the victim machines.[1][2][4]

Enterprise T1114 .001 电子邮件收集: Local Email Collection

RedCurl has collected emails to use in future phishing campaigns.[1]

Enterprise T1070 .004 移除指标: File Deletion

RedCurl has deleted files after execution.[1][2][4]

Enterprise T1218 .011 系统二进制代理执行: Rundll32

RedCurl has used rundll32.exe to execute malicious files.[1][2][4]

Enterprise T1082 系统信息发现

RedCurl has collected information about the target system, such as system information and list of network connections.[1][2]

Enterprise T1102 网络服务

RedCurl has used web services to download malicious files.[1][2]

Enterprise T1046 网络服务发现

RedCurl has used netstat to check if port 4119 is open.[4]

Enterprise T1119 自动化收集

RedCurl has used batch scripts to collect data.[1][2]

Enterprise T1020 自动化渗出

RedCurl has used batch scripts to exfiltrate data.[1][2]

Enterprise T1087 .001 账号发现: Local Account

RedCurl has collected information about local accounts.[1][2]

.002 账号发现: Domain Account

RedCurl has collected information about domain accounts using SysInternal’s AdExplorer functionality .[1][2]

.003 账号发现: Email Account

RedCurl has collected information about email accounts.[1][2]

Enterprise T1056 .002 输入捕获: GUI Input Capture

RedCurl prompts the user for credentials through a Microsoft Outlook pop-up.[1][2]

Enterprise T1566 .001 钓鱼: Spearphishing Attachment

RedCurl has used phishing emails with malicious files to gain initial access.[1][4]

.002 钓鱼: Spearphishing Link

RedCurl has used phishing emails with malicious links to gain initial access.[1][2]

Enterprise T1202 间接命令执行

RedCurl has used pcalua.exe to obfuscate binary execution and remote connections.[4]

Enterprise T1564 .001 隐藏伪装: Hidden Files and Directories

RedCurl added the "hidden" file attribute to original files, manipulating victims to click on malicious LNK files.[1][2]

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

RedCurl has created scheduled tasks for persistence.[1][2][4]

References