Malicious PDF — malware analysis report

Static analysis result for SHA-256 33ac823ade6fda7c…

MALICIOUS

PDF

79.5 KB Created: 2021-09-06 20:07:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 6c19026f103bf79852046bfe499a6a7a SHA-1: 00d9e166d612fc6d1d5861a51596fd8104f4175c SHA-256: 33ac823ade6fda7cccbd86e6bafd88b850f706d9a44be2141df389fb5662a696
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The ML classifier and ClamAV both strongly indicate this PDF is malicious, specifically flagged as phishing/trojan. The document contains numerous links pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the nature of the URLs and the heuristic firings point towards a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/71b8cee26dd20f1f331b73cfa72d68f3/ravuvoxupiza.pdf In PDF document text
    • http://lbs.ac.at/wp-content/plugins/super-forms/uploads/php/files/47staa8q1ajo7imf6addimjq5b/61127215265.pdfIn PDF document text
    • http://duocthientam.com/uploads/ckfinder/files/negixetuzaz.pdfIn PDF document text
    • https://www.ediliziaindustriale.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099a61c4a32a---80897606967.pdfIn PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609617571d049---loropegubotigodokiwon.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd5fb19610f---kunazurutawodaxefulipa.pdfIn PDF document text
    • http://marcth.pl/media/fck/file/varalifimexomeburujatida.pdfIn PDF document text
    • http://brenno-tojestto.pl/userfiles/file/6719490115.pdfIn PDF document text
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/a3786564505d733430f581a5c21ffdfd/kilofonabidugenaj.pdfIn PDF document text
    • http://abwnickersonplaza.com/uploads/files/foduxujobujowuw.pdfIn PDF document text
    • http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4693988a3a---pejixifebu.pdfIn PDF document text
    • https://spaslask.pl/wp-content/plugins/super-forms/uploads/php/files/b48ho2h1mms576e8tnr5fn8j8c/13631341486.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607afca01b9f4---91056906682.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8f1860ecc0---vibikaziganosuziziw.pdfIn PDF document text
    • http://odesignlab.ru/admin/ckfinder/userfiles/files/soberabidunixizimaw.pdfIn PDF document text
    • http://sibleyestateplanning.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/83212707445.pdfIn PDF document text
    • http://tele-video.ru/upload/files/nawesi.pdfIn PDF document text
    • https://teenvolunteerdallas.org/wp-content/plugins/super-forms/uploads/php/files/eaca600993e906a8795aa70eeeab9689/gepixajadejobobutax.pdfIn PDF document text
    • https://cometsecurity.in/admin/userfiles/file/jesisosuga.pdfIn PDF document text
    • https://hagepoorter.be/files/files/nonewepuzufitinakefamoxax.pdfIn PDF document text
    • http://mediedil.eu/userfiles/files/6177750319.pdfIn PDF document text
    • http://tvoirostov.ru/ckfinder/userfiles/files/kusaxazum.pdfIn PDF document text
    • http://lilit-realty.com/wp-content/plugins/super-forms/uploads/php/files/mm9i3k4hvbej0klr0avouo2a04/pedaledumofomobokunubosi.pdfIn PDF document text
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e51d0b17c12---nilidujomudabepotavomus.pdfIn PDF document text
    • http://bjsixiang.com/jingkelun/userfiles/files/20210801055817.pdfIn PDF document text
    • http://pp-aqua.com/userfiles/files/58846746397.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=child+malnutrition+in+ethiopia+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_off0000d41d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD41D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ec2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC2F 16816 bytes
SHA-256: ae6bc5ba362d014b95d8dce8d2bca53d19ee44d23bf79c02d2c136029e26a1c0
font_02_sfnt_off000117be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117BE 10724 bytes
SHA-256: f320f3256e0ef2813b4086a4675a56d1cad4be97d97589b796ea828f1f330479