Malicious PDF — malware analysis report

Static analysis result for SHA-256 87939ab489de4a46…

MALICIOUS

PDF

101.6 KB Created: 2021-07-12 22:10:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 86b630103b50457879a92b7096ba17b6 SHA-1: 26dc0b6fd9411debc51644faf1d0ad98c35c9360 SHA-256: 87939ab489de4a468f41db6a5f5f60241077a1f1ff1d552e00e2e2284075154a
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, with heuristics indicating it contains an external URI used for SEO redirector links, specifically for a 'free-download phishing' lure. Although the document body is heavily obfuscated and unreadable, the presence of a redirector URL strongly suggests an attempt to lead the user to a malicious download or phishing page. No scripts were extracted, but the overall pattern points to a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.5877

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/qI_NY8u86tA/square?utm_term=meaning+of+social+institution PDF link annotation
    • https://static1.squarespace.com/static/60aac4e0d5abe22cec5c4b22/t/60ec7e05fd54eb0708254bf1/1626111493549/5078353580.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6cad3a95e91b59aa2418/t/60ec7714c268f363b0857e40/1626109716480/63647987598.pdfIn PDF document text
    • https://static1.squarespace.com/static/60bf6cad3a95e91b59aa2418/t/60e8f6f337da2614570c42db/1625880307878/the_magician_upside_down.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_off00012e92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E92 10504 bytes
SHA-256: 91a7dd4ee42b9be4d43cf8f3e999ccd71380f368611aff80218e662643886132
font_01_sfnt_off000146a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x146A1 17092 bytes
SHA-256: 4a5eac648a92d79ff42e760d5782c816ed36ce774de3481b8de53ca53cb85b86
font_02_sfnt_off000172ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x172ED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1