Malicious PDF — malware analysis report

Static analysis result for SHA-256 1c8b629873be2513…

MALICIOUS

PDF

85.9 KB Created: 2021-09-15 21:33:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 2ada5c479a0a6e00d9e646173fbb1e5f SHA-1: 8ca2ea3aca9ae2c5951ffabd7266470591087fcc SHA-256: 1c8b629873be2513a90a06d234c5813735623d408ed2a41c2b161d79e25b024e
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, indicating it is designed to redirect users to potentially malicious websites. Heuristics suggest it functions as a link farm, with some links pointing to compromised WordPress upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://inwebjor.ru/uplcv?utm_term=intellicast+app+for+android PDF link annotation
    • http://etabetasurvey.com/userfiles/files/80833364494.pdfIn PDF document text
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e162d92bbf---89019828360.pdfIn PDF document text
    • http://yourtruck.be/upload/ckeditor/file/98125596161.pdfIn PDF document text
    • http://aaaexpressheating.com/userfiles/file/kuvopabipaw.pdfIn PDF document text
    • http://daithanhnam.com/upload/files/27338269210.pdfIn PDF document text
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/3346cbc27f07460c376419ac43885d4c/65808413539.pdfIn PDF document text
    • http://lyzph.com/userfiles/file/Fl202109071505038638.pdfIn PDF document text
    • http://selidbe-beograd.info/files/kisoguvilirokus.pdfIn PDF document text
    • https://www.hemingway.bg/app/templates/js/ckfinder/userfiles/files/48095229005.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bbbb966121---99962753055.pdfIn PDF document text
    • http://www.anapharmata.hu/ckfinder/core/connector/php/files/18830518126.pdfIn PDF document text
    • http://lmalaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/sejedunudodapikuf.pdfIn PDF document text
    • http://docando.es/js/ckfinder/userfiles/files/birigogaruropufuritefa.pdfIn PDF document text
    • http://otestmanager.org/club/data/userfiles/file/20210912230745.pdfIn PDF document text
    • http://t-p-fortune.com/userfiles/file/nutikimuvaloxemiretalive.pdfIn PDF document text
    • http://kooijobs.in/ckfinder/userfiles/files/rezuriludulasorava.pdfIn PDF document text
    • http://www.yankey.com.tw/demo/public/editor/ckfinder/upload/user_upload/files/97909368587.pdfIn PDF document text
    • https://fjordancv.info/wp-content/plugins/super-forms/uploads/php/files/2bba32d3d2196d3168246b26fc1a5542/lalelemenogovuvipapurovo.pdfIn PDF document text
    • http://www.impactit.in/ckfinder/userfiles/files/23010688357.pdfIn PDF document text
    • http://rowadhr.com/app/webroot/upload/files/57936083904.pdfIn PDF document text
    • http://hueide.com/upload/files/39218904754.pdfIn PDF document text
    • http://bkht.vn/userfiles/file/27498614803.pdfIn PDF document text
    • http://luxmeterthai.com/ckfinder/userfiles/files/sojaw.pdfIn PDF document text
    • https://perfecthospitals.org/ckfinder/userfiles/files/30164631226.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_off0000ea76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA76 18056 bytes
SHA-256: aac31b7b53df01841474f06058dd5927fa0592bb0dccb06b6d27c135d1862fad
font_01_sfnt_off0001195c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1195C 10564 bytes
SHA-256: f143e4b989c7c0e177673f0351fb9b639d6cc10e576c6c2531337a0487845f20
font_02_sfnt_off00013190.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13190 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1