Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9471351dd0da754…

MALICIOUS

PDF

97.5 KB Created: 2021-07-20 01:55:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 7c9890b6f5937616bd70252a4f9221f5 SHA-1: fc4a32c04f718962eecf75838ffb9d96c6e2e069 SHA-256: b9471351dd0da75411f16d52e0a3dd4fe46976b9c89c148c8f3c88b78762c871
96 Risk Score

Malware Insights

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

The PDF contains a large number of links pointing to various compromised WordPress sites, indicating a link farm or SEO manipulation tactic. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the presence of numerous external URIs on potentially compromised or disposable hosting suggests a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9936

Heuristics 5

  • 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://jnfarley.com/wp-content/plugins/super-forms/uploads/php/files/u3h0j6behhh9p4292cb6f83pl0/11157238925.pdf In PDF document text
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/d24e4849d5dffef14124005766b3e707/nozobiv.pdfIn PDF document text
    • https://gitteszoneklinik.dk/ckfinder/userfiles/files/rowiboduzomesis.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f1a7dc3372---wemovamuwiw.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/209426f449d72b071f8426b82a43bfe4/zijimesiniputitajekeju.pdfIn PDF document text
    • http://businessnavigator.in/ckeditor/uploads/files/gakadinifimibumi.pdfIn PDF document text
    • https://teenvolunteerdallas.org/wp-content/plugins/super-forms/uploads/php/files/1f97d6c5984a5c30397a0214b975451c/68836419696.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/94a45a82f0851d194c3d1176192c6b96/wewudujevuzedarevulej.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088c98a79172---96290981492.pdfIn PDF document text
    • https://roofmed.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608bdb72b6413---sezifigojevu.pdfIn PDF document text
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9b24b18088---muwunulorabaninemokedan.pdfIn PDF document text
    • https://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/cfe8b2656a2925645f8844e0a8552464/lelomaratawus.pdfIn PDF document text
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607110ac8428e---nogigulaterusatugijoba.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160acef8644225---fuzurubidugoxuxupe.pdfIn PDF document text
    • https://www.beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/68e22a2b1ebb58e2e918ba485a498fb0/93799782063.pdfIn PDF document text
    • https://havanic.com/cache/fck_files/file/99166986667.pdfIn PDF document text
    • https://digireg.org/upload/nezirajepolimuradelox.pdfIn PDF document text
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/9e2c8f423385f197fbd80c241d9e4255/64149231504.pdfIn PDF document text
    • https://saam.vn/images/content/file/12587209730.pdfIn PDF document text
    • https://arch.ua/ckfinder/userfiles/files/sorowereladawofirotiv.pdfIn PDF document text
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a6e61b6b02a---14551089644.pdfIn PDF document text
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/g8de4mkui86maf10afbjkig114/betewuj.pdfIn PDF document text
    • https://manenshop.com/upload/files/45615669794.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607592b0e0d20---gokakosulafav.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=pre+participation+evaluation+in+sports+pptPDF 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_off00011abd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11ABD 17408 bytes
SHA-256: 81e3c3b014e094df4ff05b9725c593d58e69a66456ed1c56b61054d785c495ef
font_01_sfnt_off00014837.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14837 10536 bytes
SHA-256: 9c13f3fa1000cf0c03aaac17911a546084cfb6056667cb85d8965d83003ac3f5
font_02_sfnt_off00016062.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16062 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1