Malicious PDF — malware analysis report

Static analysis result for SHA-256 979b4bc922063fe8…

MALICIOUS

PDF

97.1 KB Created: 2021-06-25 13:34:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 248afaa83b583bc22bdd3a658925e7bf SHA-1: 0a4744934d0f159a8ac1f8048d4e00794843c41d SHA-256: 979b4bc922063fe801c80f15dd05cc4406a6cae58349c110502251a16830ba4f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with numerous embedded URLs pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or malware distribution scheme. The document body was unreadable, but the presence of many external links strongly supports the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608122af94eb8---38916199487.pdf In PDF document text
    • http://vladjurnalist.ru/archive/file/gidapewofimavofogel.pdfIn PDF document text
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/6b74559925700e87320b3b6bd5b5284c/76530492541.pdfIn PDF document text
    • https://fmpride.com/wp-content/plugins/super-forms/uploads/php/files/4e22a243643dcd2642e3ecc026f3c5ce/moferesekabuluju.pdfIn PDF document text
    • http://archinfo.ru/uploads/file/26171771871.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac124be703d---49403262383.pdfIn PDF document text
    • http://szalkasszorutacskok.hu/app/webroot/files/content/files/fepag.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081ba35214bd---55759575371.pdfIn PDF document text
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090f081821fd---zuxowizomusuxowim.pdfIn PDF document text
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9f73575a78---7436340793.pdfIn PDF document text
    • http://interwork.sk/userfiles/file/27329033100.pdfIn PDF document text
    • https://ethiquedevelopers.com/wp-content/plugins/super-forms/uploads/php/files/6a363688c2c520d645d0ff6d97402f6b/42670846958.pdfIn PDF document text
    • http://pinzimoniofiumicino.eu/userfiles/files/62577165799.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160ace16db42b5---45826412157.pdfIn PDF document text
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/jesaxebalotapowegokomi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=wow+classic+gold+farming+magePDF link annotation
    • 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_off00011a38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A38 17160 bytes
SHA-256: 2152e805e8b0c87dd373349da0d888773184c45a387bbc10ff74a7b727c4684d
font_01_sfnt_off00014701.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14701 10800 bytes
SHA-256: 56d724ce3e9099564a56f52e95a37c531da698678b614f87e07ee688e11e6e91
font_02_sfnt_off00015fb4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15FB4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1