Full Report
During a recent incident response engagement for an external organization, the BHIS ActiveSOC team investigated activity attributed to the Aur0ra ransomware group. In this incident, initial access was gained through vishing following aggressive email bombing. This foothold was followed up by the deployment of a unique C2 mechanism with noisy lateral movement & ransomware attempts.
Analysis Summary
# Incident Report: Aur0ra Ransomware Group Intrusion
## Executive Summary
The BHIS ActiveSOC team responded to a double-extortion ransomware attack by the Aur0ra group against an external organization. The attack leveraged a sophisticated vishing/email-bombing entry vector and utilized a unique Xray-core C2 tunnel masquerading as legitimate Google traffic. While the threat actor attempted large-scale lateral movement and encryption, the intervention of SOC services aimed to disrupt the noisy C2 and privilege escalation attempts.
## Incident Details
- **Discovery Date:** Approximately August 2026 (Reported 18 August 2026)
- **Incident Date:** Mid-2026
- **Affected Organization:** Not disclosed (External engagement)
- **Sector:** Not disclosed
- **Geography:** Global (Aur0ra reported in 10 countries)
## Timeline of Events
### Initial Access
- **Date/Time:** T-Minus ~12 days before extortion
- **Vector:** Email Bombing followed by Vishing
- **Details:** Attackers targeted users with 900+ aggressive emails. Subsequently, they called victims posing as the "IT Helpdesk" to "help" resolve the email issue, tricking users into providing remote access/control.
### Lateral Movement
- **Details:** Highly noisy activity including ~10,000 outbound connections per workstation via SMB, LDAP, WinRM, RDP, and RPC. Attackers attempted to add accounts to "Domain Admins" and modified GPOs to inject scheduled tasks (`DriveMap-PolicyVerify`) aimed at resetting high-value account passwords.
### Data Exfiltration/Impact
- **Details:** Files were encrypted in place without extension changes. Shadow copies were deleted using `vssadmin`. The group operates as a double-extortion entity, listing victims on a public blog.
### Detection & Response
- **Discovery:** Detected via SOC monitoring of noisy network traffic and unauthorized privilege escalation attempts.
- **Response Actions:** Identified and disrupted Xray-core tunnels, removed malicious Scheduled Tasks and Registry Run keys, and quarantined masqueraded binaries.
## Attack Methodology
- **Initial Access:** Social Engineering (Email bombing and Vishing).
- **Persistence:** Scheduled Tasks (`GoogleChromeUpdateCore`) and PowerShell scripts (`updater.ps1`) via Registry Run keys.
- **Privilege Escalation:** WinRM sessions, `net group` commands, and GPO manipulation.
- **Defense Evasion:** Masquerading (naming binaries `ChromeUpdate.exe`), TLS camouflage (REALITY/VLESS) to mimic `dl[.]google[.]com`, and Chrome TLS fingerprinting.
- **Credential Access:** Attempts to reset domain passwords via GPO-deployed tasks.
- **Discovery:** `net user /domain` and `net group "Domain Admins" /add`.
- **Lateral Movement:** WinRM, RDP, SMB, and RPC.
- **Impact:** Encryption of local files and deletion of Volume Shadow Copies.
## Impact Assessment
- **Financial:** High (Ransom demands and IR costs).
- **Data Breach:** Double-extortion; data exfiltrated to group's negotiation portal.
- **Operational:** Disruption of services due to encryption and noisy network saturation.
- **Reputational:** High risk due to Aur0ra’s public victim blog.
## Indicators of Compromise
- **Network Indicators:**
- `172[.]86[.]116[.]200:443`
- `151[.]244[.]30[.]43:443`
- SNI camouflage: `dl[.]google[.]com`
- **File Indicators:**
- `ChromeUpdate.exe` (SHA-256: `15c2d007954ac53ba69b80ec91242786b3c0b71d52649165b4ca1d5cc96ef8f1`)
- `updater.ps1` (SHA-256: `05679c26f3c993270e23874442a45af486af542f3c82fd7b001c56714e89de66`)
- `!!!README!!!DO_NOT_DELETE.txt`
- **Behavioral Indicators:**
- Sudden spikes in SMB/WinRM traffic (10k+ connections).
- `vssadmin delete shadows /all /quiet` execution.
- Unsigned binaries running from `\ProgramData\GoogleUpdate\`.
## Response Actions
- **Containment:** Terminated active Xray-core C2 sessions and blocked known C2 IPs.
- **Eradication:** Deleted malicious scheduled tasks and registry keys. Removed `updater.ps1` and masqueraded `ChromeUpdate.exe` binaries.
- **Recovery:** Restored GPOs to their original state and monitored for re-infection through persistence hooks.
## Lessons Learned
- **Vishing Vulnerability:** Users are susceptible to phone-based social engineering when preceded by high-stress technical issues (email bombing).
- **C2 Sophistication:** Threat actors are moving toward sophisticated proxy tools (Xray-core) that can effectively bypass basic traffic analysis via TLS camouflage.
- **Noisy Movement:** High-volume automated lateral movement remains a primary detection trigger.
## Recommendations
- **User Training:** Implement specific training for vishing and emphasize that IT Helpdesks will never ask for credentials or remote access via unsolicited calls.
- **Endpoint Hardening:** Restrict execution of unsigned binaries from `\ProgramData\` and `\AppData\`.
- **Network Monitoring:** Implement TLS inspection or advanced traffic analysis to identify discrepancies between SNI (e.g., Google) and the actual destination IP.
- **GPO Security:** Audit GPO changes regularly and restrict permissions to modify drive-mapping policies to a limited subset of Tier 0 administrators.