Malicious PDF — malware analysis report

Static analysis result for SHA-256 98b2d01996c9c072…

MALICIOUS

PDF

74.9 KB Created: 2021-06-11 05:33:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 685017ff0bc5f5db0fbb176e4f49302d SHA-1: 43514b83cccbcb60705f13f7b7c1f270c7b626ab SHA-256: 98b2d01996c9c0723eb6a71305d42a52c7fba110fdaf91b1075911a92d2156e9
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites, which in turn host other PDFs. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create PDF documents from web content, further supporting the lure of external links.

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://medvor.ru/uplcv?utm_term=self+assessment+form+for+employees PDF link annotation
    • https://www.sanier.pl/wp-content/plugins/super-forms/uploads/php/files/3845438nlfkccpo9ugam59h2ur/lepowugajewa.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098e1a41ffa0---lefozovibifilupa.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607d6e96129e4---62390723025.pdfIn PDF document text
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/7772f2e9477046bb8cf91bcc54515c84/47506021338.pdfIn PDF document text
    • https://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/7c148b9ca277828c1773210bd8588450/wemofaxebikefet.pdfIn PDF document text
    • http://luvnchrlysenglishtoys.com/clients/861429/File/27362059912.pdfIn PDF document text
    • http://aep-tc.com/cache/fck_files/file/8364179446.pdfIn PDF document text
    • http://mg001.cn/upload_fck/file/2021-5-18/20210518072718202508.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/1jhuu1vcv53a67ii4ir0ejle08/36501920367.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/160a5b9c69da8f---84697213096.pdfIn PDF document text
    • http://oldtimerclub-thueringerberg.at/images/file/tizafevibumojujikuwi.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/q4ctopks2tkuiokrqpc698ak1i/86632715011.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607622d552869---bimuxatajitexebarukejex.pdfIn PDF document text
    • https://ddriu.hu/wp-content/plugins/super-forms/uploads/php/files/4a74f145cb3cc4945379c62b36f6c6a6/zaxabazajetum.pdfIn PDF document text
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075010386288---60042163350.pdfIn PDF document text
    • https://absolut-fit-and-dance.de/wp-content/plugins/super-forms/uploads/php/files/f5lc6m9pp28t4uhm39lbtgmph9/vidafabufi.pdfIn PDF document text
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/424b19573c153f26555019e669f2bc3a/23041581906.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e999.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE999 5252 bytes
SHA-256: 1b871497717a43364a646f6f905b83579104de190b68b654fcf3d22cab1b381b
font_01_sfnt_off0000fb69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB69 10304 bytes
SHA-256: 91108e1b62497ef175522215ca4b369fc997e72ccdff1adfd13c1f08d3af10b3