Malicious PDF — malware analysis report

Static analysis result for SHA-256 33a35381c775d436…

MALICIOUS

PDF

79.3 KB Created: 2021-06-09 03:59:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: e5df7a9b19e0efb053c7f6d98fbb6e2b SHA-1: f5a1c76e21e76ad604b08eb4b5eed2ef5e36c3c3 SHA-256: 33a35381c775d4366417af8be54af42b91ca8f9ae2647cd649fd7560d5d15fe0
156 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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.
  • 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://crewmak.ru/uplcv?utm_term=upstar+tv+input+blocked PDF link annotation
    • https://coloreverything.love/wp-content/plugins/super-forms/uploads/php/files/406493c952b6e651973ce04bda3b0d8b/kodow.pdfIn PDF document text
    • http://chono.mn/uploads/userfiles/files/pekovurumujebemixeri.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/179976c94ae50aa5d0e1816fad27bc2d/95068551682.pdfIn PDF document text
    • http://andreagarciam.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086192036422---41549339078.pdfIn PDF document text
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/751d1e335bac1e920243faa8639def94/mawowimigifabutiwurarira.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160945c4e7fa05---gukixamefitiwosekafif.pdfIn PDF document text
    • https://www.surajinformatics.com/wp-content/plugins/super-forms/uploads/php/files/effc211e1e16a75d9d4b4f6797e06088/modesilakazuveduwisopo.pdfIn PDF document text
    • http://talleresjpg.es/img/file/81365488360.pdfIn PDF document text
    • http://bertrandetgastineaudesigners.com/userfiles/file/verurufunesuno.pdfIn PDF document text
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/b558bb847788fb054f525319554b937a/zedizapazomemafovide.pdfIn PDF document text
    • http://edanieltour.com/FileData/ckfinder/files/20210601_FCF4A69EE200B7FA.pdfIn PDF document text
    • http://www.lnk-creation.fr/upload/file/29516613567.pdfIn PDF document text
    • http://fw-simple.com/uploads/files/14749160154.pdfIn PDF document text
    • http://webscape.co.bw/wp-content/plugins/formcraft/file-upload/server/content/files/1608d1ff041659---ropimixokaturugifufe.pdfIn PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/ct3s362526hjgtmr0qagp0oj72/73909111650.pdfIn PDF document text
    • http://tokyoto.pl/UserFiles/file/69010585864.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/b3f48428909ec26b820acca357405c84/91042195104.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e8a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8A0 5204 bytes
SHA-256: b23f36f545812782508e409f27ffb23960ff86b5607355d3b9414dc287f2b997
font_01_sfnt_off0000fa5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA5A 11324 bytes
SHA-256: cb1f7b11650379433f77618a17f4a4f431c762e2d89ce6aaa31c7383c34baa0f
font_02_sfnt_off000120e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120E6 4324 bytes
SHA-256: ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3