Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d1e3919b1f6e3da…

MALICIOUS

PDF

81.4 KB Created: 2021-09-19 07:50:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: f43c71e12637ea6bc35ea2caeb5a66f2 SHA-1: 894aa26cd34af5bcf072476b56478268ca9558f4 SHA-256: 8d1e3919b1f6e3da0add7c3802d035018d248b6c5af7238ef7f7cf2eb7d1b594
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF contains numerous links to various domains, many of which are hosted on compromised or disposable infrastructure, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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://landtop.com/filespath/files/20210909115453.pdf In PDF document text
    • https://bocion.com/ckfinder/userfiles/files/92067149668.pdfIn PDF document text
    • https://walterchiropracticclinic.com/home/walter/public_html/ckfinder/userfiles/files/labilenavovudivoti.pdfIn PDF document text
    • http://milwaukee.center/userfiles/file/86003927849.pdfIn PDF document text
    • http://www.nomorcantikjoss.com/file/maraso.pdfIn PDF document text
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142401f21fb6---rivutibixo.pdfIn PDF document text
    • https://jsptti.com/ckeditor/ckfinder/userfiles/files/72624642914.pdfIn PDF document text
    • https://mklaassen.nl/images/file/11262463867.pdfIn PDF document text
    • https://www.ediliziaindustriale.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613da2156400d---84269539206.pdfIn PDF document text
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/5e38d10db4be3665ea395f31efaa398e/60614599820.pdfIn PDF document text
    • http://taihegas.com/filespath/files/20210901080107.pdfIn PDF document text
    • http://salt17.com/userfiles/files/67035173901.pdfIn PDF document text
    • https://www.idd.no/ckfinder/userfiles/files/60323269911.pdfIn PDF document text
    • http://ashokarefrigeration.com/userfiles/file/malowutixewapazajo.pdfIn PDF document text
    • https://pustelnik-budownictwo.pl/ckfinder/userfiles/files/69572553740.pdfIn PDF document text
    • http://bitite.lv/media/txt/122/file/61851933294.pdfIn PDF document text
    • http://vodnik48.ru/content/file/nilenizonetagotesof.pdfIn PDF document text
    • https://bharatiyabhashaparishad.org/ckfinder/userfiles/files/63757472007.pdfIn PDF document text
    • https://prestinieurope.com/userfiles/files/38070784026.pdfIn PDF document text
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/4pehm5m0gefq2mso9gerfv2s9c/bugase.pdfIn PDF document text
    • https://inwestorfinanse.pl/userfiles/file/livujotelarevawik.pdfIn PDF document text
    • https://artesapanaderia.xyz/aym_image/files/sivubunopa.pdfIn PDF document text
    • http://surestegc.org/documentos/file/59453887924.pdfIn PDF document text
    • http://boston.pl/fck_pliki/file/feketepebowotuxefu.pdfIn PDF document text
    • https://andhimazhai.com/images/files/84573999559.pdfIn PDF document text
    • http://hypotekaprezamestnancov.sk/res/file/vibarizepabu.pdfIn PDF document text
    • https://maftplayer.net/calisma2/files/uploads/suzepixi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=how+to+take+a+screenshot+on+note+20+ultra+5gPDF 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_off0000d5e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5E0 11064 bytes
SHA-256: cfa694214a7d11376b3906ec6a9bc6da743063f982024690ecc1bdd6d921a461
font_01_sfnt_off0000efc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFC7 18388 bytes
SHA-256: c106a160831c9463970a24e0783a8ac93ed57373e9037e0d3b2e43d7416601da
font_02_sfnt_off00011fb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FB0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1