ARECHCLIENT2 via GHOSTPULSE

Summary

Elastic Security Labs traced a Windows infection chain that opens with a page imitating Cloudflare's anti-bot check. The page reports each visitor's address to an attacker-run host, then places a shortened-link fetch on the clipboard for the victim to paste into the Run dialog. What arrives is an archive holding a benign decoy executable beside a rogue DLL, so the GHOSTPULSE loader starts by sideloading. One encrypted file alongside carries both the loader's configuration and its own second stage; a separate image file, tagged IDAT, holds the payload for later. A further .NET loader neuters AMSI, decrypts its cargo with a key lifted from a PE section, and starts ARECHCLIENT2 — also known as SectopRAT — in memory. The two lure domains sat on an advertising agency's compromised server, and a banner-hash pivot from the hardcoded C2 addresses mapped further live nodes.

What changed since publication

The accounts above describe these indicators as they were on the day each was written. We re-check them ourselves and record every check, including the ones that find nothing — which is the only reason the gaps below can be stated rather than hidden.

Indicators checked

1 of 56

Checks recorded

2

Checks since publication

2

Never checked

55

Observation window 2026-08-10 to 2026-08-22. Checks are sampled, not continuous; the sampling policy is on /methodology. 55 indicators have never been checked by us at all.

Nothing has changed state between our first check and our most recent one. A domain that still resolves is not necessarily still serving anything — registrar hold pages answer DNS indefinitely, which is why the state above distinguishes “parked or suspended” from “resolving”.

Execution mechanisms

How the pasted command actually ran, as the published accounts describe it. Every row under “Mechanism” is one this campaign records; “Across the corpus” is the share of the 44 published campaigns in this corpus that record the same one — a baseline we can only state because we hold the whole set.

No other campaign on record combines them. We record a mechanism only where a source describes one: an absent mechanism means nobody wrote it down, not that it did not happen.

Indicators

56 indicators, each present verbatim in at least one of the sources above. Values are shown defanged and are not links to the hosts — the link goes to our page for that indicator.

“Assessment” is who controls the host, not how dangerous it is. Many of these are compromised legitimate sites whose owners are victims, and they are excluded from every blocklist file we publish.