Malicious PDF — malware analysis report

Static analysis result for SHA-256 e85b51d4c496a244…

MALICIOUS

PDF

69.4 KB Created: 2021-10-03 07:28:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 439fd3ecd24b2044a47aaeddb7397326 SHA-1: f44f5d3b4e506d423ba65a75b47a4a3c568747ad SHA-256: e85b51d4c496a24449c422593eb13e280ecdbcf091b7813b6010721b2ce863fc
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm pointing to multiple compromised websites, including WordPress upload directories, suggesting an attempt to obscure the final malicious destination. ClamAV detection and ML classification strongly indicate malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://nomylo.ru/uplcv?utm_term=f3sih+lewis+structure PDF link annotation
    • http://changzhou.chinatupai.com/web/js/ckfinder/userfiles/files/54201525032.pdfIn PDF document text
    • http://nuovojob.com/userfiles/files/53812801934.pdfIn PDF document text
    • http://designerhouse.ru/upload/files/nuburolorobenele.pdfIn PDF document text
    • https://sandp-engineering.com/ckfinder/userfiles/files/lovulajaga.pdfIn PDF document text
    • http://mediasingrid.com/js/new/fckeditor/userfiles/file/18108285304.pdfIn PDF document text
    • https://tahubunting1.com/contents/files/11598082872.pdfIn PDF document text
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1613c7abc6386d---sunixelagerire.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16139f797cc22e---tujotevezek.pdfIn PDF document text
    • http://colegiosantarosa.com/uploads/imagem/file/tiwubelojuridagenoxoxufew.pdfIn PDF document text
    • http://studiodugnani.it/userfiles/files/22911152854.pdfIn PDF document text
    • http://eshop-kocicinadeje.cz/files/file/34240277937.pdfIn PDF document text
    • http://ersatzmonitor.de/userfiles/file/54014740066.pdfIn PDF document text
    • https://simondaulte.com/ckfinder/userfiles/files/kefatajirikupupi.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/161412ac5db787---talepi.pdfIn PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/1a72bef8c3a8d055fb28c8b656bfb116/31169689000.pdfIn PDF document text
    • http://zhfangyuan.com/uploadfiles/files/jefukaxa.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/263ceb3a10cf2b0cf9b2e6d5bd9a8c71/piwux.pdfIn PDF document text
    • http://ahcxdq.com/uploads/file/030144162639.pdfIn PDF document text
    • http://izmirtavla.com/upload/file/2119129761.pdfIn PDF document text
    • http://tattooindex.nl/images/uploads/jizijitubogodo.pdfIn PDF document text
    • http://bagodilovaspark.hu/userfiles/file/65354817331.pdfIn PDF document text
    • https://hchoanglong.vn/userfiles/file/30830387844.pdfIn PDF document text
    • https://semangkabiji.com/contents/files/94232268052.pdfIn PDF document text
    • http://mzch.pl/userfiles/file/xovopalajof.pdfIn PDF document text
    • https://www.posluh.hr/ckfinder/userfiles/files/zubemepupisaja.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_off0000b143.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB143 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c95a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC95A 10276 bytes
SHA-256: 65b9722e74c7cc3c0e0767b6cbd3980f7c1ccd785931c378619aad4f8fed8ba7
font_02_sfnt_off0000e0af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0AF 15680 bytes
SHA-256: 018b33ca032e30d9930ec78cb8f238048e222615856ba621bd71bef7809a4743