Malicious PDF — malware analysis report

Static analysis result for SHA-256 631fd3132e981b31…

MALICIOUS

PDF

90.4 KB Created: 2021-09-08 12:09:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 1b79429040aa38912b5c918c9d2e3fe6 SHA-1: 04befe4f6e7143d473c7ab4755af1608f9a1e3b7 SHA-256: 631fd3132e981b31ba81b16dab54e388d966ebcaa745f1d0079270db6650e643
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains a link farm pointing to numerous compromised WordPress sites and other disposable hosting, suggesting an attempt to distribute malicious content or phish users. The presence of external URIs and link farms strongly indicates a malicious intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 7

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://cructi.ru/uplcv?utm_term=management+accounting+for+non+specialists+pdf PDF link annotation
    • http://winecellarkeeper.com/ckfinder/userfiles/files/50130262620.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/ja9h7a7anrn92svvtvvrbb9d8i/popufedositesuwepadubidus.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/16113ff4222b66---25841595130.pdfIn PDF document text
    • https://massagetheory.ca/wp-content/plugins/super-forms/uploads/php/files/cd9f7dfff0512ff5c04d5165b7e79f0c/medesedatekibimiw.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc5b02a40ec---pumaludigojekufama.pdfIn PDF document text
    • https://lesartsdansmonjardin.com/userfiles/file/20210715092405.pdfIn PDF document text
    • https://cosalesrep.com/wp-content/plugins/super-forms/uploads/php/files/76ffbfc5836a7cd0713610e50377be1b/33411582947.pdfIn PDF document text
    • https://rintrans.com/files/1916805323.pdfIn PDF document text
    • http://profm.hu/files/file/rajedoluj.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d0a60d5aefd---36124553519.pdfIn PDF document text
    • http://skrn.cz/pic/file/97084271694.pdfIn PDF document text
    • http://backkwang.com/userData/board/file/91262639255.pdfIn PDF document text
    • http://aldo-ins.com/userfiles/file/zukukirikavud.pdfIn PDF document text
    • https://linardi.ru/files/file/53159164832.pdfIn PDF document text
    • http://www.allatpatikapecs.hu/images/file/zusujinoxuzi.pdfIn PDF document text
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/160a10b0a83430---jalateso.pdfIn PDF document text
    • http://studiomarazzi.eu/userfiles/files/96347875810.pdfIn PDF document text
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160b0c19b30728---sexaf.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1609eb22263f6f---80814297148.pdfIn PDF document text
    • http://michalpavlicek.com/uploaded/file/40643721642.pdfIn PDF document text
    • http://luxcottage.ru/stroykamen/userfiles/files/20071418308.pdfIn PDF document text
    • http://bakoca.hu/files/file/28752942131.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_off0000f912.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF912 18664 bytes
SHA-256: 218dbd6ee950feae666b4a5ec32ec606f9330a995766cf7fbc81a828f3ae6d6e
font_01_sfnt_off00012a29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A29 11056 bytes
SHA-256: 2fff2145765a59c4c63e24b04a64883529eec8ecbaa811b25c138ee9c3d738eb
font_02_sfnt_off000143ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x143AC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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