Malicious PDF — malware analysis report

Static analysis result for SHA-256 43ec73f7926d2f51…

MALICIOUS

PDF

87.9 KB Created: 2021-08-14 03:23:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: c08696a8e1ff9fc66727adea2ebae911 SHA-1: 307ca448ad15d5af53649708db5a6bf3c0bbb442 SHA-256: 43ec73f7926d2f51fc7f65746a46cdd0289438d03b97360cd29aff6bb220f989
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised WordPress upload directories or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://krisoc.ru/uplcv?utm_term=lecturas+cortas+para+ni%C3%B1os+de+septimo+grado+con+preguntas PDF link annotation
    • http://waypl.pl/upload/File/nusimefovonasugewijug.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/ojedikodezonipo.pdfIn PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ce203bf67e---89728869094.pdfIn PDF document text
    • https://doublehair.center/upload/ckfinder/files/56028228784.pdfIn PDF document text
    • http://tiga.co.th/ckfinder/userfiles/files/kidejuxojokovanagejopudel.pdfIn PDF document text
    • http://beloezoloto.ru/userfiles/file/newep.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1608c1f9e92aad---fogenekupaseripezewe.pdfIn PDF document text
    • https://queensflower.nl/clientfiles/vadamivematikidexux.pdfIn PDF document text
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/160714c567fddb---11750028701.pdfIn PDF document text
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/1607705a1ab1ec---86875021265.pdfIn PDF document text
    • http://cuspsurgeons.com/userfiles/file/79935750420.pdfIn PDF document text
    • http://accessibilite-salle-eau.com/ckfinder/userfiles/files/249825716.pdfIn PDF document text
    • http://gw73patriots.com/clients/1/1e/1ed986c9d410becccfd9995a8318e329/File/darasitekug.pdfIn PDF document text
    • http://phuocthuan.vn/images/pic/file/nodinamazavibakasojuv.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/160977f441790a---97640491535.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/461e276f8e470b6ea0caec67736cb4c0/nosakifekiz.pdfIn PDF document text
    • http://aldara-latinoamerica.com/userfiles/file/putudidojet.pdfIn PDF document text
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1607e83509fb6b---53849349843.pdfIn PDF document text
    • http://dlmberatung.ch/userfiles/files/20658285250.pdfIn PDF document text
    • https://condominiovillage.com/userfiles/file/beturugediremodezujatixi.pdfIn PDF document text
    • http://dokumsuzgec.com/userfiles/files/94940672512.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/vurimejojanumejivido.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_off0000eefb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEFB 17788 bytes
SHA-256: 35ff3209acd4ac91ca0f95290fed5e5e4bc0aeb8c33a3b15e17d982ce50fb3d0
font_01_sfnt_off00011c7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C7D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013494.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13494 11076 bytes
SHA-256: 3d23c319ab027547577d3093987d34a6154c5a929a412cd01bf5de5a67491946