Malicious PDF — malware analysis report

Static analysis result for SHA-256 b951a4c698c5c1df…

MALICIOUS

PDF

90.8 KB Created: 2021-09-06 03:59:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 70f04022f173c7d141e8b62e8d85fe78 SHA-1: 1dcaf5a759d83e656a87c6a81fea3fb0dec2400c SHA-256: b951a4c698c5c1df5b01129695251bff0064e7187e38be0ed13bbfc6599ca211
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites and disposable domains, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, rather than user-facing text.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://willmarlakesarea2040.com/ckfinder/userfiles/files/40955653438.pdf In PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/1ndqfue05tbt8sqmnrim20ne65/rotomolewipajekasotiradu.pdfIn PDF document text
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/b7744c084994bea05a8b8845a97fec22/47405010409.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/op5nd7ppfbi1jittoje42gtus6/mokotalagukoduzodofodip.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608e1752916d9---61396671675.pdfIn PDF document text
    • https://truck-diagnostic.ru/wp-content/plugins/super-forms/uploads/php/files/f6209c15c81f81391e305d43397f4059/78311581860.pdfIn PDF document text
    • http://perfecthospitals.com/ckfinder/userfiles/files/kejopepixojetorigeli.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b96c2eced2b---38132870888.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/160aaf4ad3903a---fupuwegufagefogavuragor.pdfIn PDF document text
    • https://rmp-traueranzeigen.de/cms/files/tigadonibope.pdfIn PDF document text
    • http://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/2ddf96c99fb08830e64e00433de21f3d/56992921663.pdfIn PDF document text
    • http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/16087a995cfa25---96352942956.pdfIn PDF document text
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/m8bucsjqdl50vavqpfld87fit0/36972527396.pdfIn PDF document text
    • https://alshamiltrading.com/alshamilfiles/file/fuvenixanonuvaf.pdfIn PDF document text
    • http://kondicionery-krasnogorsk.ru/upload_picture/file/40354042925.pdfIn PDF document text
    • https://majorsagilekvaros.hu/uploads/file/gawafuzoxomakenu.pdfIn PDF document text
    • https://tyeetomsfishing.com/userfiles/file/98303388871.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/iu93pru91f9nrcrt4p24o7fon0/ludalativ.pdfIn PDF document text
    • http://clinicacomciencia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ab01b5d84f4---sefokumamijedudopil.pdfIn PDF document text
    • https://gpagroup.in/wp-content/plugins/formcraft/file-upload/server/content/files/16086833a892fd---punewujapewegubojidevusa.pdfIn PDF document text
    • https://razvozka24.ru/wp-content/plugins/super-forms/uploads/php/files/e3d501a05d8ef25ab4a1e7cd4be94f1a/80367470001.pdfIn PDF document text
    • http://familiehollander.nl/images/uploadedimages/file/xisuvolelotumogobugejuso.pdfIn PDF document text
    • http://www.southforconstruction.com/frontend/web/ckfinder/userfiles/files/xavamuloxezinitexodaduj.pdfIn PDF document text
    • http://santamariamikado.com/uploads/files/jibososolulamesavazas.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=cancer+de+esofago+y+estomago+pdfPDF 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_off0000fd13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD13 10968 bytes
SHA-256: 1939c0c08f962c89555dedf5af005a9033c1f8121598c24db2f14da0bf5faf9b
font_01_sfnt_off00011663.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11663 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012e75.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E75 18468 bytes
SHA-256: 48f1d729c5575ec1a9fb54d02b816c3da160d23841bd09a045b8b580a42a100d