Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef9ba2a5d7540e68…

MALICIOUS

PDF

85.6 KB Created: 2021-08-17 02:42:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 026aa371a1a277f784180051623e7710 SHA-1: 16eb15e6cbb69b21b0b60e0aada05f68751aae61 SHA-256: ef9ba2a5d7540e688ebcccf8e00c5e9ca4811951a3b4d4f11c43302cb38c52d9
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised CMS upload directories, suggesting it's designed to lead users to malicious content or phishing sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution via a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://kientrucqhouse.com/uploads/image/files/puriwizorobusoxuxoriw.pdf In PDF document text
    • http://bora.su/ckfinder/userfiles/files/gudavudelewinareparapedo.pdfIn PDF document text
    • https://eurouniversal.eu/ckfinder/userfiles/files/zetesijejujavi.pdfIn PDF document text
    • https://bio-obst-und-gemuese.de/userfiles/file/77141622251.pdfIn PDF document text
    • http://savvyais.com/userfiles/file/basivigu.pdfIn PDF document text
    • http://alwaditrading.com/userfiles/files/39794092466.pdfIn PDF document text
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/6d836f73d3011a7b65b8ef3cc56fb780/gobakakipatoxewubo.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160e264708b662---wotesakajovinedusupulu.pdfIn PDF document text
    • https://rmp-traueranzeigen.de/cms/files/kiribolobix.pdfIn PDF document text
    • http://vipavtoufa.ru/wp-content/plugins/super-forms/uploads/php/files/7bdd30c8c31920f724c8e06e57b4576e/86087486845.pdfIn PDF document text
    • https://curryleafharleysvillepa.com/hang/userfiles/files/zevedevasuwaxubopovetek.pdfIn PDF document text
    • http://cesnek-vysocina.cz/UserFiles/File/13015591639.pdfIn PDF document text
    • http://animalscipublisher.com/files/upfiles/file/kenurugusoba.pdfIn PDF document text
    • http://amuseonline.com/absite/userfiles/file/gagixawo.pdfIn PDF document text
    • https://magazinul-de-instalatii-sanitare.ro/app/webroot/files/userfiles/files/90958757278.pdfIn PDF document text
    • https://www.idahomedia.com/wp-content/plugins/super-forms/uploads/php/files/0375f9f578861b132efb18b5ea375bfa/86983372969.pdfIn PDF document text
    • http://castrolmintabolt.hu/images/upload/file/18691960488.pdfIn PDF document text
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160923b8d51015---79639864332.pdfIn PDF document text
    • http://ikra-ekb.ru/files/fckeditor/file/93226669120.pdfIn PDF document text
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160ade2f62b99e---nazajozesejisisogure.pdfIn PDF document text
    • http://bukharageorgia.com/sites/default/files/file/turijofexebebi.pdfIn PDF document text
    • http://musiconthebay.org/clients/2/26/269dd5bc96e197da989a8dccc71442af/File/girovu.pdfIn PDF document text
    • https://sindonis.com/userfiles/file/gedewasadimodub.pdfIn PDF document text
    • http://alacarte-design.de/userfiles/file/55643787029.pdfIn PDF document text
    • https://lightsourceindiana.com/wp-content/plugins/super-forms/uploads/php/files/d2526be2f58fca5dd4a6e27c2249a379/jujuwaru.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=what+is+the+role+of+assistant+administrative+officerPDF 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_off0000e92b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE92B 17504 bytes
SHA-256: a8aa97a613e1973600ffd0f58368cb0492fbcc2e9969c813984bfdf995e8a4b6
font_01_sfnt_off00011700.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11700 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012f17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F17 10800 bytes
SHA-256: 5aad82d23823f756c4c60a3084e0920477f20dfcb82e1cc1e8f3c3761837a26d