Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d431f4275876ca6…

MALICIOUS

PDF

79.0 KB Created: 2021-09-20 06:17:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: f6a53e6bdb1c3a7bbc581fc55844c592 SHA-1: 34bb7ce027b8a39aabb1e077f315f5e6c0c79fed SHA-256: 4d431f4275876ca6a4d9e2f80c32d02b86dbecede89e632bae8a03898bb88fd6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URIs are indicative of a phishing lure, potentially leveraging embedded JavaScript for obfuscation or redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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 https://synerhu.ru/uplcv?utm_term=vademecum+academico+de+medicamentos+descargar+gratis+pdf PDF link annotation
    • https://birsamundapark.in/userfiles/files/fefirut.pdfIn PDF document text
    • http://fabrykakonwersji.pl/wp-content/plugins/super-forms/uploads/php/files/6660be672b209301235a0bbe7460776e/logaguxojozov.pdfIn PDF document text
    • http://freeski.hu/freeski/file/jezigaxubuvuzixofo.pdfIn PDF document text
    • https://globalcircle.club/userfiles/file/61344603868.pdfIn PDF document text
    • https://mudrun.com/home/mud/public_html/ckfinder/userfiles/files/ziraxewalo.pdfIn PDF document text
    • https://ichibaninfotech.com/ckfinder/userfiles/files/51228704243.pdfIn PDF document text
    • http://tongchangkj.com/uploadfile/file///2021090615040136.pdfIn PDF document text
    • https://uleiuri.ro/userfiles/file/27120279611.pdfIn PDF document text
    • https://nguoixunghekiev.vn/userfiles/file/25322849667.pdfIn PDF document text
    • http://aliguoriarchitetto.eu/userfiles/files/topomaw.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613776faef455---dikipaj.pdfIn PDF document text
    • http://xn--djr00fsyfv0o5qgy9u.com/filespath/files/20210902153433.pdfIn PDF document text
    • http://csc-0411.com/userfiles/file/20210910170835_pfj8x9.pdfIn PDF document text
    • http://sloplast.com/userfiles/files/38924873618.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/57929111349.pdfIn PDF document text
    • http://www.gc-antey.ru/ckfinder/userfiles/files/1906610991.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613104bae18bb---66781615436.pdfIn PDF document text
    • http://ikhmongol.mn/ckfinder/userfiles/files/94896343423.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c761617c82---40467407188.pdfIn PDF document text
    • http://szolnokepul.hu/userfiles/file/vurezabuzefozonanomamu.pdfIn PDF document text
    • https://krusomying.com/data/file/xofasuwivinivugiw.pdfIn PDF document text
    • http://specimport.by/files/files/86868099569.pdfIn PDF document text
    • http://ceramicaartisticamarsalese.it/userfiles/files/tedipu.pdfIn PDF document text
    • https://holycrosshealthcare.com/userfiles/files/sirugawozeletujeretuzilo.pdfIn PDF document text
    • https://congthuonghotel.vn/app/webroot/files/images/pages/files/6938717202.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_off0000c81e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC81E 10988 bytes
SHA-256: ae2ff1ba2ff5052eb7c4401c82772bd67b6ed6973e98743118e08a17e0bddd33
font_01_sfnt_off0000e16b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE16B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f97d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF97D 20168 bytes
SHA-256: d999ab3815db42b2c35addfb0558b5dda21690a50ae793abcad198daf7c496fa