Malicious PDF — malware analysis report

Static analysis result for SHA-256 a90b6edc5be7e7b3…

MALICIOUS

PDF

84.9 KB Created: 2021-07-13 10:55:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: c9b3f2bd46b950e5fbdfef8d22e833f3 SHA-1: 34fb759c77d2592bf65662ac52436b8884ce3b29 SHA-256: a90b6edc5be7e7b3478b1788b06b0b9c3214fdb3751e82972550ab2d76433092
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a phishing attempt. The 'PDF_SEO_UTM_REDIRECTOR_LINK' heuristic specifically points to an image lure linking to a redirector, which is a common tactic for phishing. The embedded URL, while marked as benign, is part of the redirection chain. The document body is heavily obfuscated and unreadable, suggesting an attempt to hide its malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6359

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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/sq/ugae/~3/jEScUJLm1bs/square?utm_term=what+pokemon+need+a+shiny+stone+to+evolve PDF link annotation
    • https://static1.squarespace.com/static/60bf69b23f3791685666e32d/t/60ed17333b21860fe66d5f52/1626150707766/77691064772.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6bff0d8d387fecc8b153/t/60ec7aa3d0153e73bf8aef83/1626110627148/91123657114.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac4e0d5abe22cec5c4b22/t/60ec89086ad76c097490cee9/1626114312932/91362534301.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_off0000ea3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA3B 16544 bytes
SHA-256: a1fb8a7afa3f185aed4014e7cde81146b0468bd4bfc640a22e3b7c518fd33e0c
font_01_sfnt_off0001150c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1150C 10824 bytes
SHA-256: d9764fa6e62ae237634083e70fee08beedd5dfeeb9c3b1b120a8de56367c33d8
font_02_sfnt_off00012de8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DE8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1