Malicious PDF — malware analysis report

Static analysis result for SHA-256 c731cd25de0186e0…

MALICIOUS

PDF

83.0 KB Created: 2021-09-20 13:25:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: c7bdff29a4324079e215ce8378ba56af SHA-1: b887d34957067510b3b9ded546c0f1ab5b273896 SHA-256: c731cd25de0186e04381b5e4d1824327d0bc6f07a1dc9431dce8581e46cdbdb4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to compromised websites and disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a malicious document, potentially leveraging embedded JavaScript for malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://pistant.ru/uplcv?utm_term=made+with+vivavideo+apps PDF link annotation
    • http://alpes-maritimes.proximeo.com/ckfinder/userfiles/files/rujafivuwakufag.pdfIn PDF document text
    • http://forti.in/userfiles/file/54776124416.pdfIn PDF document text
    • https://biroestarsa.hu/uploads/file/xijuxogefelafil.pdfIn PDF document text
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/ec9b3ea96a476d1cd05cedc9d15e7925/denadovibefukiku.pdfIn PDF document text
    • http://dxline.eu/userfiles/file/82818563568.pdfIn PDF document text
    • https://thehouseproduction.net/file/kegowulotinaxovurep.pdfIn PDF document text
    • https://vyrukrc.lt/userfiles/file/romobezosopufej.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16139bce599a1d---redukidorikulug.pdfIn PDF document text
    • https://tktravelkorea.com/FileData/ckfinder/files/20210916_AA5B18C48EBE7A95.pdfIn PDF document text
    • https://letajicikoberce.cz/userfiles/file/pituda.pdfIn PDF document text
    • https://dobski.pl/userfiles/file/45821656806.pdfIn PDF document text
    • https://bloomeng.com/uploads/nuxazaxewotujuru.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c66dc84952---sovibujugi.pdfIn PDF document text
    • http://dayuntang.com/assets/uploads/ckedit/files/20210914141811.pdfIn PDF document text
    • http://xn----otbb6ahq3d.xn--p1ai/ckfinder/userfiles/files/fuxalilebum.pdfIn PDF document text
    • http://hejia-ele.net/upload/4783378413.pdfIn PDF document text
    • http://dxczx.com/ckfinder/userfiles/files/20210904_234508.pdfIn PDF document text
    • http://eugensa.lt/app/webroot/uploads/userfiles/files/rebosezoremejatotet.pdfIn PDF document text
    • http://lawyergz.net/uploadfile/files/mikokosekuvikatizumigi.pdfIn PDF document text
    • http://xn--42-jlclgg6a3e.xn--p1ai/userfiles/file/jonatukupoz.pdfIn PDF document text
    • http://wasserburg.pl/userfiles/file/valisoxelikulis.pdfIn PDF document text
    • https://www.rt9.rspo.org/ckfinder/userfiles/files/51507832293.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_off0000de44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE44 18916 bytes
SHA-256: 2c7a0cfdefb9c700c93a670ab388131ae4a284e9a5f179cc1cf62036ba470648
font_01_sfnt_off00010ebf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EBF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000126d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126D6 10384 bytes
SHA-256: db7653eb1953ce31b43c0d5de47044fcebec798fb156a403d0f38516bbce029e