Malicious PDF — malware analysis report

Static analysis result for SHA-256 839d6bd43bb00817…

MALICIOUS

PDF

94.2 KB Created: 2021-06-30 02:48:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: d9422862479e4da7f14a95be71398d78 SHA-1: 6abfc3f742dd1722d5e68595ccca3d2d5a2be1c4 SHA-256: 839d6bd43bb008176cf155e76075ffa04ce1dcd6693b75d4cdfb98c4e539e272
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple compromised WordPress sites and disposable hosting, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. No scripts were extracted, but the structure and embedded URLs are indicative of a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://www.straightmyteeth.com/wp-content/plugins/super-forms/uploads/php/files/b4a9d45436a4733c78a0254ca79a3451/kadojo.pdf In PDF document text
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/fe23bb766ec3ad110ff01092745a1a9d/38731636070.pdfIn PDF document text
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/2gnnilus2nvlg9ungqpsim648t/80320592157.pdfIn PDF document text
    • http://nagymester.com/userfiles/file/pizenuvebagamuzo.pdfIn PDF document text
    • http://www.gaviprintpack.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a66cf578a07---40883637541.pdfIn PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/1609f776be1dff---pidifiruvolorul.pdfIn PDF document text
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160893db18471d---52720482711.pdfIn PDF document text
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/929b636207cfdcb2e9f5e76f30b857bd/vukobazezepofetezepobetuk.pdfIn PDF document text
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/642500a9cb9fde0665958413dd1d8e3d/68286937201.pdfIn PDF document text
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/08c76a1cbd48138f224c4c05a22eb82d/wujajawemab.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/d1edf18bc46ef0f33ce57ad5d5b47760/nufumaliw.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16091bd7bca895---25212662817.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2e1956c4f8---banadanukiwevelod.pdfIn PDF document text
    • https://yellowstonewildlife.com/fanavudekakamimowu.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/gofuk.pdfIn PDF document text
    • https://www.harnoordesigns.com/wp-content/plugins/super-forms/uploads/php/files/h81bbo819ahjgsmrvl9t5fct22/86847928164.pdfIn PDF document text
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/08a7b3f37f3a04d6dd505ef624c6152e/favojefipamawakig.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a33c04431f---53926091196.pdfIn PDF document text
    • http://acpiindia.com/userfiles/file/xixisevotifewolimelab.pdfIn PDF document text
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/c77a16fa55d1a890694c7e2ee863232a/bemubumop.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a7b536c6471---binumokidoxu.pdfIn PDF document text
    • http://sicompk.com/survey/userfiles/files/wizarorefuru.pdfIn PDF document text
    • https://home18.ru/wp-content/plugins/super-forms/uploads/php/files/6cf59c7d884e063430de32bc2008d3d7/49391160406.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=time+of+your+life+tony+robbins+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_off00010bc6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BC6 18048 bytes
SHA-256: 53662fa037d5f1793fc29967beaa2ff8c66b4481f8fd087009dc0f47f50ce90a
font_01_sfnt_off00013b42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B42 10816 bytes
SHA-256: 0cbea2d8e1039e408483c70916412fa0c9f25a4b90498ee7f2eedb45659ee288
font_02_sfnt_off000153fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x153FA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1