Malicious PDF — malware analysis report

Static analysis result for SHA-256 c804f9b754b63fc3…

MALICIOUS

PDF

71.1 KB Created: 2021-09-26 01:55:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 90d37e8d84ccc6a00e04e59010b686b2 SHA-1: 6f13f23ec9777eb4f9af5779172b0c4fa3348e9c SHA-256: c804f9b754b63fc3710b3585301cfa36f4c43a1205f547b5a1b6008ef97bf98b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of embedded URLs, many of which point to disposable hosting or compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The structure suggests a link farm designed to obscure the final destination and evade basic detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://pistant.ru/uplcv?utm_term=thomson+dictionary+apk PDF link annotation
    • http://nanouklid.cz/upload/file/komawes.pdfIn PDF document text
    • http://ganteltechnology.com/system/userfiles/file/68891845400.pdfIn PDF document text
    • http://dentish.ru/ckfinder/userfiles/files/92450804760.pdfIn PDF document text
    • http://elskenecologie.nl/files/20131364366.pdfIn PDF document text
    • http://allineers.netlovestories.com/upload/files/torovo.pdfIn PDF document text
    • http://civicwomen.com/ckfiles/files/37508886385.pdfIn PDF document text
    • http://kunbot.com/upload/files/99085724456.pdfIn PDF document text
    • http://vincentianssjp.com/userfiles/file/9337730805.pdfIn PDF document text
    • http://niszczeniewaw.pl/userfiles/file/tibopezifiwikaze.pdfIn PDF document text
    • https://marblo.ph/app/webroot/img/files/mazabulinugejob.pdfIn PDF document text
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134022f274b5---11235258018.pdfIn PDF document text
    • http://tiendanatacion.com/noticias/files/zozujawe.pdfIn PDF document text
    • http://baovephuongtroi.com/vietkiendo/upload/file/89122901425.pdfIn PDF document text
    • https://webhosting4.net/media/file/27899425975.pdfIn PDF document text
    • http://recuva.kr/upload/fck_img/1631350961/file/buxetutajiwowe.pdfIn PDF document text
    • https://agape4u.org/userfiles/file/wamojetosixefidutixexawit.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/161470f723a448---xesumarotoxokejupupo.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/jasatasokakera.pdfIn PDF document text
    • https://bjjewels.net/nbloom/fckuploads/file/kasufivupigu.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1614152f087a61---84526159969.pdfIn PDF document text
    • https://pacientes.quiroser.com/UserFilesQUI/file/rabek.pdfIn PDF document text
    • https://skopjemuzikon.pmgrecordings.com/ckfinder/userfiles/files/30410884866.pdfIn PDF document text
    • https://equalland.com/uploads/File/pebisis.pdfIn PDF document text
    • http://easyreturn.store/userfiles/file/39144440746.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_off0000b477.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB477 16116 bytes
SHA-256: bf32727ea425885a69b2c32993300907e62a8678d415b404342502b805fe4b29
font_01_sfnt_off0000ddc6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDC6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f5dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5DD 10768 bytes
SHA-256: 0fbb172ccb861ca7f7bfa1587dce8b20813178008e0ad32fac2dd8830503bdd2