PCAP investigation summary

What happened

The host 10.0.0.167, associated with the account elmer.obrien, downloaded a PE (portable executable) file via HTTP from 119.31.234.40 using the URL http://alphapioneer.com/spool/8888.png; the file's hash is f6210da7865e00351c0e79464a1ba14a8ecc59dd79f650f2ff76f1697f6807b1.

This PE file download used a .png file extension, which is not a typical method for transferring executables and is flagged as highly suspicious, requiring further investigation of the payload's hash; no proof of execution or infection is present.

A separate ZIP archive was also downloaded by 10.0.0.167 from 158.69.28.93, but there is no evidence yet linking this file to malicious activity within the supplied coverage.

Who was involved

• 10.0.0.167 (host DESKTOP-GRIONXA, user elmer.obrien) is the device that downloaded the suspicious PE file.

Key indicators

• SHA-256 hash f6210da7865e00351c0e79464a1ba14a8ecc59dd79f650f2ff76f1697f6807b1 identifies the downloaded PE file and should be reviewed to determine maliciousness; no threat intelligence verdict is returned at this time.

Supported technique candidates

• Downloading a PE payload from the internet is consistent with ATT&CK technique T1105 (Ingress Tool Transfer) but execution or adversary activity is not confirmed.

What remains uncertain

• It remains unknown whether the suspicious executable was run or if any malicious behavior resulted from its presence on 10.0.0.167.

Next check

• Obtain and analyze the dropped executable (hash: f6210da7865e00351c0e79464a1ba14a8ecc59dd79f650f2ff76f1697f6807b1) from 10.0.0.167 for static and dynamic properties to assess its intent and execution on the host.

Analyst-review draft. Exact evidence references and provider provenance are retained in the structured record.