Malicious PDF — malware analysis report

Static analysis result for SHA-256 c77cfeebebd52872…

MALICIOUS

PDF

91.0 KB Created: 2021-09-17 09:13:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 7daf09524c91501e67475e5cfcbc1d95 SHA-1: bca9bf956e167fd34c6d77e8a2ffb0e72e8545fa SHA-256: c77cfeebebd528723a8100bc6e2613a5de0291cdc54e74bb8f86bee35b9f2e2e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are consistent with a malicious PDF dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9929

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://nomylo.ru/uplcv?utm_term=take+off+malayalam+movie+torrentz2 PDF link annotation
    • http://condominiobrisasdelnorte.com/userfiles/file/43153414065.pdfIn PDF document text
    • http://buzmakov-ua.ru/admin/ckfinder/userfiles/files/28191044715.pdfIn PDF document text
    • http://wintec-samu.hu/uploads/files/kisoxo.pdfIn PDF document text
    • http://csc0532.com/userfiles/file/20210901100050_cepn9m.pdfIn PDF document text
    • http://crediramasrl.it/public/file/xikabotug.pdfIn PDF document text
    • https://northwestconvention.cz/data/files/dipuro.pdfIn PDF document text
    • http://in-dapt.com/wp-content/plugins/formcraft/file-upload/server/content/files/161378eb2dc7f7---24431103509.pdfIn PDF document text
    • http://inbjnews.com/data/cheditor/0603/files/32557765910.pdfIn PDF document text
    • http://szyuangang.com/UserFiles/file///11772386962.pdfIn PDF document text
    • https://sowlindia.com/userfiles/file/99600349678.pdfIn PDF document text
    • http://dinhvi5s.com/images/newtech/files/16107588868.pdfIn PDF document text
    • http://ngocminhcnc.com/demo_thietbimay_24_7/upload/files/54294262726.pdfIn PDF document text
    • https://jeevandeepspecialcare.com/ckeditor/ckfinder/userfiles/files/6890958863.pdfIn PDF document text
    • https://garnizone.com/userfiles/file/sonoxogepulupe.pdfIn PDF document text
    • https://kopari.hu/files/file/32442269305.pdfIn PDF document text
    • https://pluviaterra.mx/wp-content/plugins/super-forms/uploads/php/files/b0fbbd187ec011c7fdfe0628791f49f0/15583007096.pdfIn PDF document text
    • http://dreiseengrundschule.de/files/249203167.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613f259d759ae---1232884227.pdfIn PDF document text
    • https://sgcaregiver.org/contents/files/58305918046.pdfIn PDF document text
    • https://ixiu-23.com/uploads/files/202109042337428037.pdfIn PDF document text
    • http://asupuro.com/upload/save_image/files/70817122180.pdfIn PDF document text
    • http://shtaket46.ru/page_edit/_samples/userfiles/files/gezesujobegekiwotuf.pdfIn PDF document text
    • http://cesurmakina.com/userfiles/file/24380102747.pdfIn PDF document text
    • http://kursverwaltung.fit-n-essen.ch/ckfinder/userfiles/files/78905709705.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138ba861b0a8---67245585970.pdfIn PDF document text
    • 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_off0000fdfb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDFB 18344 bytes
SHA-256: 7858e40d153e6efbd0ca028cbf1522ff9e43e49631936ed9751967e9cd2e5fc2
font_01_sfnt_off00012e18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E18 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001462f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1462F 10624 bytes
SHA-256: 3d5b95cf223b726071affeab7ba46a2a3a073a0bb68e7dd9a48f4601fb89c4c1