Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c62664f517361ab…

MALICIOUS

PDF

81.2 KB Created: 2021-09-11 21:26:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: bb44ec9c0ceeb60b2af5f2fc10575cf7 SHA-1: 2fbc513772de72819817ed5607028e4736d9c7c0 SHA-256: 8c62664f517361ab575c957429ca41a71887147bec384212c66717a42a693f3c
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed for malicious redirection. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The heuristics indicate the document is structured as a link farm, potentially to bypass security measures or for SEO poisoning.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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 http://aardbeienfeesten.nl/uploadimages/files/lazat.pdf In PDF document text
    • http://tecs4.com/intranet/ckfinder/userfiles/files/47951451309.pdfIn PDF document text
    • http://secureyun.cn/uploadfile/file///2021091116185885.pdfIn PDF document text
    • http://kool-house.com/upload/editor/file/54579681529.pdfIn PDF document text
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/4ea29361e66eddbddf04b6dde0b400e0/22163012308.pdfIn PDF document text
    • http://mojahotels.com/ckfinder/userfiles/files/98852202275.pdfIn PDF document text
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/161340f22989a6---24921450605.pdfIn PDF document text
    • https://detskeihriska.eu/ckfinder/userfiles/files/52605352288.pdfIn PDF document text
    • http://candleelectricals.com/uploaded_files/userfiles/files/24691026134.pdfIn PDF document text
    • http://beccaro.it/userfiles/files/depavofewukugogaloru.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b71a601ae2---liresufegiwaxogarilo.pdfIn PDF document text
    • http://xn--ob0bjxt9h99icicrvkksa421cwwp7hiv4d6a.com/ckfinder/userfiles/files/sijaneb.pdfIn PDF document text
    • http://gonganmi.com/userfiles/file/14430090605.pdfIn PDF document text
    • https://ddshower.com/ckfinder/userfiles/files/tojer.pdfIn PDF document text
    • http://freetds.net/userfiles/file/9919374316.pdfIn PDF document text
    • https://camerabentrenet.camerabentre.vn/ckfinder/userfiles/files/rokovejevutuviket.pdfIn PDF document text
    • http://recviem.ru/img/upload/51361193043.pdfIn PDF document text
    • https://asiapharma.la/files/files/78910063913.pdfIn PDF document text
    • http://pure-chiral.com/upload/files/tabuvoxetala.pdfIn PDF document text
    • http://videocycling.info/files/file/63868294301.pdfIn PDF document text
    • http://tecs4.com/intranet/ckfinder/userfiles/files/41477891721.pdfIn PDF document text
    • http://mweb.cz/images/file/wixebatavozudake.pdfIn PDF document text
    • http://doingthing.com/downloads/blog/geust/files/81501056594.pdfIn PDF document text
    • http://aallergy.netlovestories.com/upload/files/69239513844.pdfIn PDF document text
    • https://jesssmithtri.com/jesssmith/ckfinder/userfiles/files/36921706271.pdfIn PDF document text
    • http://matras-devison.com/upload/file/xalowuxexozipuzedonuvaj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=penelope+ward+books+read+onlinePDF 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_off0000d9bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9BC 17480 bytes
SHA-256: 55023980033e0570b48fed40d93f0d8e6c1f034068209ffe6fcd665bcbb82bf7
font_01_sfnt_off00010720.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10720 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011f37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F37 10608 bytes
SHA-256: 8f0a36bcc14cf8082f5f0075db3ab5822d13aedb151cab0989d4c959a10083d1