Malicious PDF — malware analysis report

Static analysis result for SHA-256 73539d9a9357878a…

MALICIOUS

PDF

76.1 KB Created: 2021-09-02 01:32:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: ac7878c1c26687dea1ea7d6277b3994e SHA-1: b8e08a71f0097270f7d7d9ac98de37916f839150 SHA-256: 73539d9a9357878a097d29893d245263113267e4c535b4cf3c733a8eaee07897
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is often used to exploit vulnerabilities or redirect users to malicious sites. Several heuristics indicate the document is a link farm pointing to compromised WordPress uploads, suggesting an attempt to host malicious content or phishing pages. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7ca6824c93---95288584479.pdf In PDF document text
    • http://www.extramas.com/userfiles/files/45967998721.pdfIn PDF document text
    • http://keletunderground.hu/images/uploaded_pics/file/kurametatu.pdfIn PDF document text
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/f80e2d3d83a11f6c9664276b992fa547/34359091243.pdfIn PDF document text
    • https://groupunsur1.com/contents//files/58248530971.pdfIn PDF document text
    • http://rdmsrl.it/userfiles/files/vupaxuvos.pdfIn PDF document text
    • http://tanabuauto.com/js/upload/files/viwonozulaxisuvo.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d2f53f1b3eb---62794476396.pdfIn PDF document text
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/e7e7add216433a648ea0f5528d62728b/11890383454.pdfIn PDF document text
    • https://study-go.info/wp-content/plugins/super-forms/uploads/php/files/7c9bc130bc3d59dd7e0094b136e16f86/84740673339.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/0e42f6155f7a0e879928ad7bf38f8b31/33554692717.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608951fa3f517---52931595907.pdfIn PDF document text
    • http://contrast.no/ckfinder/userfiles/files/rusesureduresa.pdfIn PDF document text
    • http://soles2walk.cz/data/file/majulivovigalo.pdfIn PDF document text
    • http://www.polni.si/Images/files/83831812333.pdfIn PDF document text
    • http://tiszaikaland.hu/upload/file/75725042229.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=composition+of+functions+answer+keyPDF 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_off0000c67b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC67B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000de92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE92 11016 bytes
SHA-256: e44e89e9b381474171e464b2cf058bd62155f97180387da3bcf5fc421100d553
font_02_sfnt_off0000f859.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF859 16460 bytes
SHA-256: fc66cf30d018e57bfc554fcc4bc3b7e834d2148120a9560b707f60524d6cabf8