Malicious PDF — malware analysis report

Static analysis result for SHA-256 0c36ccf190c410f4…

MALICIOUS

PDF

81.6 KB Created: 2021-09-07 06:54:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 5389f9fad2eb9c1bbdaaf10ac6d2a589 SHA-1: 6f0191a3059b20d45da657e50e56c61d8913ad79 SHA-256: 0c36ccf190c410f4ca628cbd20bc07e927e898d9c97a3e060910d1a847867c86
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, lacking clear user-facing content but containing structural elements indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://chi-kara.net/Upload/files/lukemajenovojenotaka.pdf In PDF document text
    • http://polletnv.be/uploads/files/wajefanotod.pdfIn PDF document text
    • http://bukharajohnscreek.com/sites/default/files/file/429531596.pdfIn PDF document text
    • https://hantverksakuten.se/ckfinder/userfiles/files/2484891599.pdfIn PDF document text
    • http://szyoujin.com/UploadFile/file/20210828040506486.pdfIn PDF document text
    • https://www.travelticket.com.au/wp-content/plugins/super-forms/uploads/php/files/ihca5ee4lo0aj13sim383nljse/70983421834.pdfIn PDF document text
    • http://naturallabs.fr/userfiles/file/lolatulokonoside.pdfIn PDF document text
    • https://zazilha.com.mx/wp-content/plugins/super-forms/uploads/php/files/aa3f9de7e372583b51050f73ee0be397/9652528463.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac6abba0de3---zuwox.pdfIn PDF document text
    • https://springkasteelhuren.be/userfiles/file/kowediwokaruzozenamuza.pdfIn PDF document text
    • http://terapeutickemasaze.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160b2092ceb771---29326169176.pdfIn PDF document text
    • http://inlikeflintlogistics.com/wp-content/plugins/formcraft/file-upload/server/content/files/160eca78b26078---vatajurifuko.pdfIn PDF document text
    • http://hatowo.com/app/webroot/uploads/files/tozabutuvujufimat.pdfIn PDF document text
    • http://fabrykakonwersji.pl/wp-content/plugins/super-forms/uploads/php/files/3096d97cdddb6d80d8e7903fbf71f091/sepaxobajadi.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160d7615a71605---55283105734.pdfIn PDF document text
    • http://flywings.sk/UserFiles/file/85259821684.pdfIn PDF document text
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/30bc9f658143cf23ad15f1ef50973397/2233671205.pdfIn PDF document text
    • https://am-system.eu/ckfinder/userfiles/files/fafumebafugamakeda.pdfIn PDF document text
    • http://mognational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074f8ee1be35---dokewawaver.pdfIn PDF document text
    • https://www.nestroots.com/wp-content/plugins/super-forms/uploads/php/files/16ammile9qj78fh7c93nvbi2v6/lunagororovi.pdfIn PDF document text
    • https://ibrahimkoc.com/images/Media/files/80874418730.pdfIn PDF document text
    • http://giftboxvietthuy.com/upload/ck/files/31306568921.pdfIn PDF document text
    • https://brunoamaranti.it/wp-content/plugins/super-forms/uploads/php/files/2ee7gribptb5bv5mgnq412p1p4/75408172512.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160713f18d12e6---68251825590.pdfIn PDF document text
    • http://metabolit-plus.ru/files/file/xiwazadi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=engineers+day+speech+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_off0000daeb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAEB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f2fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2FD 17488 bytes
SHA-256: 70b0b8f07faf93789f362d2edd438fc3c9678235ad62f362fe258925fccef0ed
font_02_sfnt_off00012050.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12050 10732 bytes
SHA-256: cc706937ad32ed4c9f95cc8642097e94b22e52ea70deec1d2e97f3b94713d5ab