How can organizations detect ransomware that does not rename files?

Security teams should configure EDR and SIEM solutions to detect sudden spikes in write operations and high file entropy changes within short timeframes, especially when initiated by non-system processes, rather than relying solely on filename monitoring.

Primax Hit by Aur0ra Ransomware Group | Femto Security Threat Intelligence

Key Takeaways

The Aur0ra ransomware group successfully targeted Corporación Primax S.A., exfiltrating sensitive database and configuration files.
Aur0ra utilizes a stealthy encryption technique that modifies file contents without renaming files or changing extensions, bypassing basic EDR rules.
The threat actors utilize double-extortion tactics, demanding a ransom payment under the threat of releasing the stolen enterprise records publicly.
Defenders must shift detection methods toward high-entropy file analysis and behavioral monitoring to identify non-renaming ransomware families.

Original source screenshot for Primax Compromised by Aur0ra Ransomware Group — Original source screenshot - u6lieui2dakbctcjea2bz4r4q32r7t36nwljovqbv7mxs6o2smgxixid.onion

Aur0ra Ransomware Incident Severity

Critical double-extortion threat posing high risk to industrial energy sector databases and credentials.

0.0

/ 10.0 custom

CRITICAL

Aur0ra Exfiltration and Exposure Metrics

Mapped Fuel Stations

POS Transaction Volume

0 GB

Affected Workforce PII

Aur0ra Targeted Intrusive Flow

1Initial Accessmedium
Unsecured remote services, exposed RDP/VPN, or phishing
medium
2Executionhigh
Execution of Go-based payload with active defense evasion
high
3Exfiltrationhigh
Silent retrieval of databases, AD keys, and OT network maps
high
4Silent Encryptioncritical
In-place file contents altered without changing extensions
critical

Threat Actor: Aur0ra Ransomware Group

Aur0ra

aka Aurora

Motivation: Financial (Double Extortion)
Targets: EnergyManufacturingSpace-Materials R&DLogisticsRetail
TTPs: Silent encryption (no filename change)Go-based multi-purpose malwarePre-encryption data exfiltrationTor negotiation chat portals

Aur0ra Indicators of Compromise (IoCs)

domain
exposedrecords.io
Data Leak Site (DLS)
domain
exposedrecords.io
Data Leak Site (DLS)
url
http://ijexszhscln27nl263lmcd7tx3jttkhm4wjhd4e3y6r4csdbfyeprvid.onion
Tor Negotiation & Chat Portal
url
http://ijexszhscln27nl263lmcd7tx3jttkhm4wjhd4e3y6r4csdbfyeprvid.onion
Tor Negotiation & Chat Portal
url
http://u6lieui2dakbctcjea2bz4r4q32r7t36nwljovqbv7mxs6o2smgxixid.onion
Tor Negotiation & Chat Portal
url
http://u6lieui2dakbctcjea2bz4r4q32r7t36nwljovqbv7mxs6o2smgxixid.onion
Tor Negotiation & Chat Portal
url
http://pavregldzg2ypbd3gxbil2suxfok7ykmcknwhkli24anpks6lndymyyd.onion
Tor Leak Site & File Server
url
http://pavregldzg2ypbd3gxbil2suxfok7ykmcknwhkli24anpks6lndymyyd.onion
Tor Leak Site & File Server

Technical Mitigation & Containment Strategy

Progress0 / 4 (0%)

Isolate Subnets & Segment Networks
Ensure complete separation between IT corporate networks, OT environments, and fuel stations.
Enforce Active Directory Key Rotation
Revoke database strings, SFTP credentials, and rotate domain administrator master keys.
Deploy Entropy-Based SIEM Rules
Track high-frequency write anomalies of high-entropy content to non-renamed database paths.
Configure Firewalls to Drop Tor Traffic
Block corporate DNS resolving onion addresses and terminate direct outbound routing to Tor exit nodes.

How to Defend Against Similar Threats

Implement behavioral entropy-based EDR rules to detect high-volume file modification events that lack name changes.
Isolate IT corporate networks from OT networks and retail fuel station environments to limit lateral movement during a ransomware attack.
Perform a complete rotation of database connection strings, Active Directory master keys, and system administrator passwords.
Run continuous external vulnerability assessments to identify and patch exposed remote access gateways and unauthenticated VPN systems.

Threat Intel FAQ

What is unique about the Aur0ra ransomware encryption method?

Unlike traditional ransomware that appends a visible extension to locked files, Aur0ra encrypts the internal contents of files while keeping the original filenames intact. This silent approach allows the malware to bypass EDR detection mechanisms that monitor file-renaming patterns.

What data was reportedly stolen during the Primax incident?

The threat actors claimed to have exfiltrated extensive enterprise datasets from the energy company, including system configurations, internal database parameters, customer transaction parameters, and a file designated as Dbdata.json.

Could a similar threat affect your organization?

If your team may be exposed to a similar threat, FemtoSec can help validate blast radius, prioritize remediation, and connect the issue to a practical security program.

Primax Compromised by Aur0ra Ransomware Group

Key Takeaways

How to Defend Against Similar Threats

Threat Intel FAQ

Could a similar threat affect your organization?

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