Sh4mefulIP Address: 91.92.241.38
IP address 91.92.241.38 is registered to ORG-OL329-RIPE and geolocates to Amsterdam, The Netherlands. It first appeared in sh4meful's dataset on June 11, 2026 and was most recently observed on July 9, 2026. Over the observation window, it has failed DMARC alignment 11 times, targeting one sender domain. It has no reverse DNS record. Network context: this address sits within OMEGATECH (ORG-OL329-RIPE), a network sh4meful has observed producing 70 failures across 13 distinct IPs during the same window.
Failure Activity Over Time
Peak activity was observed in the week of July 6, 2026 with 8 failures recorded. Activity in the most recent 30-day window increased sharply compared with the prior period (12 vs 4 failures).
This IP has claimed to send from 1 sender domain monitored by sh4meful. The single targeted domain suggests either a compromised sending source or a spoofing attempt focused on a specific brand.
This page shows DMARC authentication failure data for this IP address. Learn more about this data.
Geolocation Information
- Country:
- NL The Netherlands
- Region:
- North Holland
- City:
- Amsterdam
- Coordinates:
- 52.3759, 4.8975
WHOIS Information
- Network Name:
- OMEGATECH
- CIDR:
91.92.241.0/24- Owner:
- ORG-OL329-RIPE
Analysis
This IP has generated DMARC authentication failures across 16 messages between June 11, 2026 and July 9, 2026. Every message observed from this source failed both SPF and DKIM verification. Receiving mail providers applied a reject disposition, refusing delivery outright.
The address has no reverse DNS record. Legitimate mail infrastructure almost always publishes a PTR record, because major receivers (Gmail, Microsoft 365, Yahoo) penalize or reject mail without one, and because it is a baseline operational hygiene expectation. Its absence, combined with authentication failure, is consistent with a host being used to originate spoofed mail rather than one misconfigured by a legitimate operator.
Geolocation places the host in Amsterdam, The Netherlands, on infrastructure operated by ORG-OL329-RIPE. Abuse-reporting channels in this jurisdiction are generally responsive, and reports to the network operator can result in timely remediation.
The address is registered to ORG-OL329-RIPE (OMEGATECH), an enterprise network operator. Concentrated authentication failures on enterprise address space can indicate either a compromised internal host being used as an unauthorized sending relay, or an organization knowingly or unknowingly operating as a spam source.
Across the wider OMEGATECH network, 13 distinct IPs have been associated with 70 authentication failures over 90 observed messages, spanning 2 countries. Most observed IPs on this network contribute to the failure count, suggesting the range as a whole warrants elevated scrutiny.
If your domain appears in the From header of mail from this address, treat it as probable spoofing. Verify that your SPF record does not authorize this host, directly or through nested include mechanisms, and that no DKIM selector you publish has been issued to it. If both checks come back clean, the receiver's reject action is doing its job.
Your DMARC policy posture matters more than any IP-level response here. The enforcement action applied to this mail indicates your policy is already providing protection. Maintaining p=reject across all your domains closes the gap for attackers who manage partial alignment. Domains that remain at p=none long-term tend to be impersonated repeatedly, because the cost to the attacker of attempting is effectively zero.
Blocking this individual address has limited durability: an attacker can rotate to another address in the same /24 subnet at effectively zero cost. More durable responses include monitoring aggregate DMARC reports so new sources are visible as they emerge, tightening SPF to remove overly permissive include chains or +all mechanisms, and ensuring DKIM is signing every legitimate outbound stream so alignment failures are unambiguous. The formal abuse contact for ORG-OL329-RIPE is listed in RIPE WHOIS records, and timely remediation is achievable through that channel.
External Reputation Lookups
Look up this IP in external threat intelligence and reputation databases (opens in new tab):
Nearby IPs
The following IP addresses share the same /24 subnet as 91.92.241.38 and have appeared in sh4meful's dataset. Related activity in nearby addresses often indicates infrastructure operated by a single actor or provider.
- 91.92.241.223 — 1 failure, first seen 3 months ago, 78 days before this address.
Recommended Action
If this IP appears in your own DMARC reports, treat it as an unauthorized sender unless you have specifically verified it as a legitimate service you use. Ensure your DMARC policy is at p=quarantine or p=reject to prevent delivery of messages this IP claims to send from your domain. If you're new to DMARC, our complete guide walks through the mechanics.