Lazy SRE's guide to secure systems, part 4: the four DNS records
The article discusses the importance of DNS records in securing email systems against phishing attacks. It highlights a campaign called SubdoMailing that exploited weaknesses in SPF records to send millions of phishing emails. The author emphasizes the need for regular audits of SPF records to prevent unauthorized use of domains.
- ▪Guardio Labs reported a phishing campaign called SubdoMailing that sent five million emails daily using trusted subdomains.
- ▪The attack successfully passed SPF, DKIM, and DMARC checks by exploiting expired contractor domains.
- ▪The article advises organizations to regularly audit their SPF records to ensure all included domains are trustworthy.
DEV.to (Top) files mainly under programming. We currently carry 4,924 of its stories.
Story provenance
Source · retrieval · rights · ranking — open for full record
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Story provenance
Attribution is not the same as permission. This drawer separates discovery metadata, excerpts, WeSearch-generated summaries, reuse status, and whether the publisher receives the visit. Nothing here claims a legal grant the publisher has not made.
Record
| Original publisher | DEV.to (Top) |
| Canonical URL | https://dev.to/sachincool/lazy-sres-guide-to-secure-systems-part-4-the-four-dns-records-4eh4 |
| Publication time | Mon, 18 May 2026 16:58:36 +0000 |
| Retrieval time | 2026-05-18T17:04:56.667Z |
| Last seen | 2026-05-18T17:04:56.667Z |
| Headline source | Publisher (no WeSearch rewrite) |
| Excerpt source | publisher body |
| Excerpt method | First ~120 words (~800 chars) of extracted publisher body, fair-use limited. |
| Summary | WeSearch · cerebras-chat (WeSearch summarizer) |
| Summary source text | contentText |
| Citation coverage | Summary is a WeSearch-generated derivative; primary citation is the original publisher URL. |
| Cluster | popSrqcZoWvj · 2 stories |
| Cluster logic | Grouped by semantic title/content similarity across sources within a rolling window. Same-publisher template collisions are excluded from coverage comparison. |
| Ranking reason | Story pages are not engagement-ranked. Hub feeds use recency, with optional source-diversified chronological ordering (cap consecutive stories per source). No personalized ranking. |
| Publisher visit | Yes — open original |
| Substitutes article? | No — link-out required for full text |
Rights status (four layers)
WeSearch handling by dimension
| Indexing | May the item be indexed (stored, ranked, made findable)? | Allowed |
| Snippet | May a short excerpt of the publisher's text be shown? | Allowed |
| AI summary | May WeSearch generate its own short summary of the article? | Limited |
| Retrieval / RAG | May the content be exposed for third-party retrieval-augmented generation? | Not asserted |
| Model training | May the content be used to train AI models? | Not asserted |
| Commercial reuse | May the content be reused commercially? | Not permitted |
Basis: Derived from the published RSS/Atom feed. Contact: [email protected]. Reviewed: 2026-07-24.
Opening excerpt (first ~120 words) tap to expand
try { if(localStorage) { let currentUser = localStorage.getItem('current_user'); if (currentUser) { currentUser = JSON.parse(currentUser); if (currentUser.id === 324078) { document.getElementById('article-show-container').classList.add('current-user-is-article-author'); } } } } catch (e) { console.error(e); } Harshit Luthra Posted on May 18 • Originally published at harshit.cloud Lazy SRE's guide to secure systems, part 4: the four DNS records #security #devsecops #lazysre #dns Originally published at harshit.cloud on 2026-04-26. In February 2024, Guardio Labs published a writeup of a campaign called SubdoMailing. Five million phishing emails a day, sent through subdomains owned by MSN, eBay, VMware, NYC.gov, UNICEF, and McAfee. Every single email passed SPF and DKIM.
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Excerpt limited to ~120 words for fair-use compliance. The full article is at DEV.to (Top).
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