Malicious PDF — malware analysis report

Static analysis result for SHA-256 b59c8355e8e4f516…

MALICIOUS

PDF

76.2 KB Created: 2021-07-12 22:47:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 31f998e71ccf27369bbf39068af6b463 SHA-1: ed1384cbcb8f89752f62cef5de4a375e892863c1 SHA-256: b59c8355e8e4f516cb2509bb3b74ab290fd10390f56dee6a0d032e63d36825fe
136 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ClamAV as 'Pdf.Phishing.Trojan' and ML classifiers indicated maliciousness. A high-severity heuristic identified an image lure linking to an SEO redirector, which is a common phishing tactic. Although the document body is heavily obfuscated, the presence of a redirector URL strongly suggests a phishing attempt to steal user credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.7076

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/sq/ugae/~3/9xivtwLAy4k/square?utm_term=trailer+homes+for+sale+in+tennessee PDF link annotation
    • https://static1.squarespace.com/static/60aac52a97a1d73ddacfe14c/t/60e77000463f933081ef7463/1625780224659/28_day_weight_watchers_meal_plan.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac5994c6b1805bc4acbdb/t/60ec8b286ad76c0974910517/1626114856456/99059866820.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac59fb7e9621e2f466549/t/60ec88cc3f7a034ccb7b220a/1626114252341/31567590480.pdfIn PDF document text
    • https://static1.squarespace.com/static/60aac4e0d5abe22cec5c4b22/t/60e85030ad52d6438eb4153b/1625837616669/corrugated_metal_roofing_span_tables.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_off0000c8a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e0bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0BD 10440 bytes
SHA-256: bde8e8a843645337c1a8191d10252d8b6b13189fc26059a0ef9c59d982543fbe
font_02_sfnt_off0000f834.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF834 17040 bytes
SHA-256: c66c89a85c53eb551c9f45c969d4d14cbb2414aa448104d50cdb0a4eeff70d4c