Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9cf1d1df896c762…

MALICIOUS

PDF

86.0 KB Created: 2021-07-14 02:58:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 1531d1b3ca31e7d688a923eaf0f680f6 SHA-1: 049b7367418337d71dff1cd12c306efb85b77d49 SHA-256: b9cf1d1df896c762133af8df185d8c0f06042cb25832f9c490d44c2eb1869cb0
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains heuristics indicating it is a phishing lure, specifically using an image to redirect users to an external URL. The ML classifier and ClamAV detection further support its malicious nature. Although no scripts were directly extracted, the PDF structure and embedded URI suggest an attempt to lead the user to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6359

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://feedproxy.google.com/~r/razvivatel/yapz/~3/kVSxLQpkboc/square?utm_term=how+to+propagate+mother%27s+tongue PDF link annotation
    • https://static1.squarespace.com/static/60aac4e0d5abe22cec5c4b22/t/60ecaad3af807f1e15293e23/1626122963971/lyrics_when_we_were_young.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac4e0d5abe22cec5c4b22/t/60eca8da11a746407a44e1f4/1626122459037/clinical_epidemiology_and_global_health.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac4e0d5abe22cec5c4b22/t/60e7b98a6e46386ca3bebf3e/1625799050815/lelesajajamajomisojoxawo.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ef7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF7C 16776 bytes
SHA-256: 7da35c005ceb2becb54d33bdbea30c25505cd7b03fcb715e32c6d8d6ff79c5ab
font_01_sfnt_off00011b3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B3C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013353.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13353 10772 bytes
SHA-256: 2614068748c0b9e94b48640a6053aef776232255671d09b97adf4eb59b65de39