Malicious PDF — malware analysis report

Static analysis result for SHA-256 e77528f7fc980995…

MALICIOUS

PDF

88.5 KB Created: 2021-07-09 17:35:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 0da54ca3d9c4cfb41691fb4f33d935ba SHA-1: 7efcf27d1f5eebf61344a72b4fdae015af3502fb SHA-256: e77528f7fc9809952a517335312da4e118573ca80240e2909f7d6573fc01451d
164 Risk Score

Malware Insights

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

The sample is a PDF that functions as a link farm, containing numerous URLs pointing to websites, many of which are hosted on compromised WordPress installations. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure and URL findings suggest a malicious workflow.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://vickers-electronics.co.uk/wp-content/plugins/super-forms/uploads/php/files/c1b6d17205e1d5ed9080c2bcd7c8a437/guxixobosolorubunifopow.pdf In PDF document text
    • https://cedarcreeksauce.com/wp-content/plugins/super-forms/uploads/php/files/fab1b4f5375899b02585f26463c50673/zasumoxonedu.pdfIn PDF document text
    • https://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/51ae09902d569e9ed8321872c2deaf37/bisijavi.pdfIn PDF document text
    • http://erbilsunhotel.com/wp-content/plugins/super-forms/uploads/php/files/6rs7t8bgjrqgrkg6dcof7ud0n0/gezugisiwisopilojukux.pdfIn PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/49b686960a6e06d87d58808ec044a180/27139714295.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/h5kntkvp8e3bmtvrrfpfthcoa3/tejebor.pdfIn PDF document text
    • http://alphabodysupplements.com/newerac2c/userfiles/file/20541543900.pdfIn PDF document text
    • https://flycam.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1607025d4883e6---xewirixeka.pdfIn PDF document text
    • http://kawoka.com/userfiles/file/62215187758.pdfIn PDF document text
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160873870c290d---poferudowegajubavalu.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a737ad67312---xoninekozuxijudijoxutug.pdfIn PDF document text
    • http://www.redactordecontenidos.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1608e9f5303f93---wurusemepejowomizulu.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a821968adb1---savexejanowemotev.pdfIn PDF document text
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c394f63599---4478192238.pdfIn PDF document text
    • http://tantusmarina.com/UserFiles/file/31642472715.pdfIn PDF document text
    • https://loctra.net/userfiles/file/kiwipiwatifimopun.pdfIn PDF document text
    • http://photographybynami.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2feee02a5a---rubid.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/rurudug.pdfIn PDF document text
    • http://precedent.by/_newsite/images_from_html_editor/file/vajevidokuzi.pdfIn PDF document text
    • https://mebelihome.ru/upload_picture/kixubukutapen.pdfIn PDF document text
    • https://siphouse96.com/wp-content/plugins/super-forms/uploads/php/files/f3abc6fd0aad514aacb581f9c373f4a5/tefet.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6cf7ac954b---47012962430.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c966004417---31541867715.pdfIn PDF document text
    • http://www.deopendeur.org/imgUser/file/jegibobatepozuvonu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=the+little+fir+tree+questions+and+answersPDF 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_off0000f715.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF715 17160 bytes
SHA-256: 03a0994e21a0dc26e67d5e094a5357b9ac240e7bdcbcdbb8a398991b650331ff
font_01_sfnt_off00012422.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12422 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013c39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C39 10748 bytes
SHA-256: 4b06c253a12ed521a922027d1a139800a62fee39cff55b20a8ec618e6cda648f