Full Report
This report provides statistics on the number of new ransomware samples collected, the number of affected systems, and affected companies in May 2025, as well as key ransomware issues in Korea and abroad. The following is a summary of the report. Disclaimer: The number of ransomware samples and damaged systems is based on the […]
Analysis Summary
This incident report is based on aggregated statistics and trends for May 2025, rather than a single, specific incident. Therefore, most fields will reflect general threat landscape observations for that period.
# Incident Report: May 2025 Ransomware Trend Analysis
## Executive Summary
This summary covers ransomware activity trends for May 2025, detailing a decreased volume of new ransomware samples compared to April. The primary impact observed across the analyzed data is the public listing of affected companies on dedicated leak sites by various ransomware groups. Response actions and specific IOCs are not provided for a singular breach but are generalized based on underlying malware analysis.
## Incident Details
- Discovery Date: Throughout May 2025 (Ongoing monitoring)
- Incident Date: May 2025 (Aggregate period)
- Affected Organization: Multiple organizations globally (as listed on DLS)
- Sector: Various (based on DLS listings)
- Geography: Global (with specific focus on Korea in source material)
## Timeline of Events
### Initial Access
- Date/Time: Not applicable (Statistical overview, attacks ongoing throughout the month)
- Vector: Not explicitly detailed for a specific attack; general access vectors assumed based on ransomware trends.
- Details: Statistics cover the detection of new ransomware samples.
### Lateral Movement
- [Not applicable - General trend report]
### Data Exfiltration/Impact
- [Not applicable - Impact is summarized as listing on DLS]
### Detection & Response
- [Detection based on AhnLab's endpoint detection infrastructure.]
- [Response actions are implied as internal analysis and reporting.]
## Attack Methodology
As this is a statistical summary, specific TTPs are inferred based on general ransomware activity observed in May 2025:
- Initial Access: Likely involving phishing, exploitation of public-facing services, or compromised legitimate credentials (inferred).
- Persistence: [Inferred]
- Privilege Escalation: [Inferred]
- Defense Evasion: [Inferred]
- Credential Access: [Inferred]
- Discovery: [Inferred]
- Lateral Movement: [Inferred]
- Collection: Identifying valuable data for double extortion.
- Exfiltration: Data transfer for listing on DLS.
- Impact: Data encryption and public shaming via DLS.
## Impact Assessment
- Financial: Not specified, but implied through negotiation/recovery costs post-encryption.
- Data Breach: Data exfiltration occurred, confirmed by listing on ransomware DLS. Specific volume/type is internal to the report.
- Operational: Impact from ransomware encryption is implied across affected systems.
- Reputational: Confirmed negative impact due to public listing on DLS.
## Indicators of Compromise
- Network indicators: Unavailable for specific incidents (defanged: N/A)
- File indicators: MD5 hashes provided (03d02dac0e2be6a4d5d26ce6a2132fb3, 1846d5e033ab5fb00573300dc8abb992, 1c34c1860041aa479c14a9c5b332712c, 27182f9017d8e4212fbc32e954e19d37, 3e063dc0de937df5841cb9c2ff3e4651)
- Behavioral indicators: Overall increase/decrease in sampling volume observed.
## Response Actions
Specific organizational containment is not detailed; generalized actions based on the nature of the threat:
- Containment: Segmentation and isolation of detected infected systems.
- Eradication steps: Removal of identified ransomware binaries using updated signatures.
- Recovery actions: Restoring systems from verified backups.
## Lessons Learned
- The volume of malware samples is subject to monthly fluctuation.
- Ransomware groups actively maintain Dedicated Leak Sites (DLS) for publicizing victims, confirming the extortion element is central.
- Reliance on external statistics (DLS publications) is necessary for comprehensive tracking.
## Recommendations
- Continuously update endpoint detection mechanisms to identify new sample variations noted in May 2025.
- Enhance visibility into public-facing assets that may serve as initial access points.
- Maintain rigorous, tested backup and recovery procedures to mitigate DLS publication impact.