Malicious PDF — malware analysis report

Static analysis result for SHA-256 21f88c962756b8ae…

MALICIOUS

PDF

85.8 KB Created: 2021-06-29 00:29:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: e820828cddc0c1ddf95fc2e5d68d6585 SHA-1: 926a6db0bd2740f156eb9c803362770151c4c463 SHA-256: 21f88c962756b8aeb3a9218e162c5fd555b6ccc1e90227a3f72c22d8e50dab11
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised CMS upload directories, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. No scripts were extracted, but the structure and URL patterns are indicative of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/desatmg51t0d9pfq7q74eg4e07/614865250.pdf In PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c6a92288028---93543999718.pdfIn PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087db5f8fcbe---fujat.pdfIn PDF document text
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/160829fd93599e---zapetirikoj.pdfIn PDF document text
    • http://schs1968.com/clients/861610/File/72650186544.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609cb1ef72dea---96363290803.pdfIn PDF document text
    • https://awlights.com/wp-content/plugins/super-forms/uploads/php/files/6fb82a147a5e43d39ada684d3f2192e5/tuxetitu.pdfIn PDF document text
    • https://et-auditing.com/userfiles/files/pululixavepuvuf.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/974912340d315b4d54e8a749c1011217/10457581791.pdfIn PDF document text
    • http://school19-zav.ru/userfiles/file/jalugukotefe.pdfIn PDF document text
    • http://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b66924a4ddd---jenigegogetaruz.pdfIn PDF document text
    • https://www.democratum.com/wp-content/plugins/super-forms/uploads/php/files/27a7420fc350fce731fca887d898c3b0/fibepirajoput.pdfIn PDF document text
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/gokvvhptkbpu1qplpt3kqjn069/mikegivupixixokileba.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/saldtg1rhsfp1k1ol21sh3e332/31019884355.pdfIn PDF document text
    • http://toyteepee.com/uploadfiles/file/2105240532151793639y9ggn.pdfIn PDF document text
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/c1c55c8073023238ec4056ad043c466e/2811057336.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b67853c61e7---76042318151.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160aee41fd856c---bovidevilijunutum.pdfIn PDF document text
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/187e9877e8e92d7ba3a82df0320975de/bulivop.pdfIn PDF document text
    • http://savvyais.com/userfiles/file/subovisar.pdfIn PDF document text
    • https://www.schroedersales.com/wp-content/plugins/super-forms/uploads/php/files/c91a1ba483d39b6e79f66ffd3ca57484/xazemukixagof.pdfIn PDF document text
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/q9la67qcbue7sopoake7sj2d3n/10099231403.pdfIn PDF document text
    • https://hosvagyok.hu/userfiles/file/dipajupetakizozibifefix.pdfIn PDF document text
    • http://carriewoodfamily.com/clients/5/5b/5b9f2fb360c4065436fb7fe1267c3612/File/nulesepenibigijozuzoj.pdfIn PDF document text
    • https://matrainagycsalados.hu/userfiles/file/kuxipigejopumevewev.pdfIn PDF document text
    • http://xdata.pl/app/webroot/img/ckf/files/4142335947.pdfIn PDF document text
    • https://hirurgija.me//files/67890306478.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=biblical+meaning+of+strawberries+in+a+dreamPDF 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_off0000ed63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED63 11096 bytes
SHA-256: 5cd8b492db7c6c3b9409f62e760aaafbc8437d55fc7041c505fe3711791fd083
font_01_sfnt_off00010728.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10728 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011f3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F3A 16352 bytes
SHA-256: ea76927e121f6e1ce987ff7840e0ed4491796fdf0acec92f12b2d71bf2af6809