Malicious PDF — malware analysis report

Static analysis result for SHA-256 81130a5ae6c6a8c8…

MALICIOUS

PDF

79.1 KB Created: 2021-09-05 10:23:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 57e2cd71b3248eebef8e0a24b6bdf132 SHA-1: 92fc9aa61350589cf4ae4bab6247bf478d55d241 SHA-256: 81130a5ae6c6a8c8cdc7e9644fa71b4808ad33aeeb19e2c8f43adc85848f72ea
172 Risk Score

Malware Insights

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

This PDF sample was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. The presence of embedded JavaScript and numerous links pointing to potentially compromised WordPress sites suggests an attempt to exploit users, likely for downloading a second-stage payload. The heuristic findings of a 'link farm' and a 'download button lure' further support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 8

  • 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.
  • 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://rosewoodcity.org/nbloom/fckuploads/file/vejuvonalup.pdf In PDF document text
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a4fa7080aac---zuxotipulebogaj.pdfIn PDF document text
    • https://www.adelaarenergy.com/wp-content/plugins/super-forms/uploads/php/files/qhgadgpvhntuliceuc24qjrrut/7266817668.pdfIn PDF document text
    • http://maduraigarlandshop.com/userfiles/file/bapoxobomelisirizireg.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/16090267400415---vufufa.pdfIn PDF document text
    • https://www.idromeccanicasrl.com/idromeccanicasrl.com/wp-content/plugins/super-forms/uploads/php/files/c496333d7dcd690d8723d58c5c66085f/55554591757.pdfIn PDF document text
    • http://debeleven.net/UserFiles/File/73539199266.pdfIn PDF document text
    • https://beysukonaklari.com/ckfinder/userfiles/files/jetapupasujar.pdfIn PDF document text
    • http://paintmaster.hu/js/ckfinder/userfiles/files/46954029465.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160879eb0cbd4b---12478447210.pdfIn PDF document text
    • https://www.habitat-morvan.fr/ckfinder/userfiles/files/78749954043.pdfIn PDF document text
    • http://vytvarnyobchod.cz/UserFiles/File/sakebifomukujirezijimodi.pdfIn PDF document text
    • https://amenagementsoleil.com/wp-content/plugins/formcraft/file-upload/server/content/files/160704192e4370---52200809613.pdfIn PDF document text
    • http://stonebreaker.at/45024762423.pdfIn PDF document text
    • https://kermanrooz.com/img/files/99354157174.pdfIn PDF document text
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/26ccc6a2bd9a59816bd0f3cf7b99c3f6/86085861812.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b7779d7611d---71358616128.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/xofosakemetilawugimox.pdfIn PDF document text
    • https://yuktogel.com/contents//files/jobamawuvugogibizoni.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5dfebc6ae---33252105647.pdfIn PDF document text
    • http://lnshiyue.com/userfiles/file/20210818211349_207191644.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=pre+referral+intervention+manual+digitalPDF 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_off0000cf46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF46 17816 bytes
SHA-256: 2b9f27fd84c9b4c72413524490d4681740c4c85abebb7dd79ebefcf7600e195f
font_01_sfnt_off0000fe6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE6E 10696 bytes
SHA-256: 48a3bfdd2f047f34c4f660a965e36f2b80228f263b6b0cc1525fa1ca72235bbe
font_02_sfnt_off000116b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116B8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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