Malicious PDF — malware analysis report

Static analysis result for SHA-256 9e6439f7ece86d7a…

MALICIOUS

PDF

80.9 KB Created: 2021-09-08 07:13:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 1891c955b5d47dc3cef3ca6b5cf66daf SHA-1: a65f6707d209d29a2519d3f467e6e3055ba72a2c SHA-256: 9e6439f7ece86d7acefa9dfff29563711974d68245521de9e861624156e1471d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised CMS uploads or disposable hosting, suggesting an attempt to lure users to malicious sites. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, further supporting a malicious intent rather than legitimate document content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://clinivetmadonnadirosa.eu/userfiles/files/65539856101.pdf In PDF document text
    • https://attack.lt/images/files/96938901874.pdfIn PDF document text
    • http://nage-z.com/ckfinder/userfiles/files/magojikovixerapupozijem.pdfIn PDF document text
    • https://psiakocky-potisk.cz/webpagebuilder/ckfinder/userfiles/files/diwebebudumogi.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c080369f0ef---gezova.pdfIn PDF document text
    • http://christmaslandint.com/userfiles/derep.pdfIn PDF document text
    • https://agentcctv.com/userfiles/file/sepomixukopapoten.pdfIn PDF document text
    • http://atut-biuro.com/uploaded/file/48557321069.pdfIn PDF document text
    • http://hfengly.dk/skoleportalen/userfiles/file/73182781624.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609111c3270af---833985187.pdfIn PDF document text
    • https://skvacations.com/userfiles/file/3708648702.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094df2bf0a5a---39038809846.pdfIn PDF document text
    • https://essaidafm.com/uploads/FCK_files/file/27967591355.pdfIn PDF document text
    • https://imapcb.org/wp-content/plugins/super-forms/uploads/php/files/2342ed994568ba1e5116e22888eb9781/98854332591.pdfIn PDF document text
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/160c0202aa307d---fikevopuwi.pdfIn PDF document text
    • https://funbugs.ie/files/file/wedeg.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160b890a70a7dd---83322903212.pdfIn PDF document text
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/b674ae1e9c5db5f599c114d764b0a17b/12723723209.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c8b63288294---jowutolotina.pdfIn PDF document text
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d6ceeb5da47---jumolovojefuwuluzo.pdfIn PDF document text
    • http://studiopedrazzini.eu/userfiles/files/44059222003.pdfIn PDF document text
    • http://auto-spec.ca/fck/file/fonozitijesug.pdfIn PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078b75742c9d---leroviw.pdfIn PDF document text
    • http://frickcontrols.com/uploads/files/xebofubejovuguv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=central+air+conditioning+system+components+pdfPDF 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_off0000d720.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD720 17580 bytes
SHA-256: ff225e9625226278b7d695af16d964cdecd02ffeb0d55be431e7b4839fb39074
font_01_sfnt_off00010445.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10445 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011c5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C5C 11108 bytes
SHA-256: 08d7fee9a8a5cb344480c6ef3d1622800a99398165375eb50bb8675d943b738f