Malicious PDF — malware analysis report

Static analysis result for SHA-256 850f81fe5163fa71…

MALICIOUS

PDF

77.4 KB Created: 2021-08-16 11:52:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 11174761be8f309083a6b89479d0b47e SHA-1: 1cfa486c49aef625fbd44d01bab77000f4d11e48 SHA-256: 850f81fe5163fa716eec1a211058f7c481c59344d90e90adc0b6089eb17b5a85
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ClamAV as a phishing trojan and by an ML classifier as malicious. It contains numerous embedded URLs, many of which point to compromised WordPress sites and other potentially disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. While no scripts were explicitly extracted, the PDF structure and URL patterns are indicative of a malicious document, likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://client-sms.com/ckfinder/userfiles/files/70881320275.pdf In PDF document text
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072d88d5e38d---61366966003.pdfIn PDF document text
    • http://seritour.com/rsm/files/diderafigevefu.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/160982fcbd35ab---16766793196.pdfIn PDF document text
    • http://angelojrobles.com/admin_initial_test/userfiles/file/70234057479.pdfIn PDF document text
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dafa7a3de9---rigotegonoxidonofuj.pdfIn PDF document text
    • http://andreevmag.com/wp-content/plugins/super-forms/uploads/php/files/40423bb37ecb2cf654ded72fb20ca7a5/gipilulanufoz.pdfIn PDF document text
    • https://cottingham-group.com/cufiles/files/nejowodusilunid.pdfIn PDF document text
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/2badcd42c5f9e97188e1ca000cd51f51/kudulurofagiko.pdfIn PDF document text
    • http://zonazero.es/userfiles/file/rizapelobebegujebuxup.pdfIn PDF document text
    • https://farmacieitaliane.com/documenti/file/vavuxuvivoxekafuludaxeti.pdfIn PDF document text
    • https://dp-silver.com/userfiles/file/dapimabikefifaxipetawawas.pdfIn PDF document text
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/ff216e10cf708993bfa5b6f9ea30bc53/milazudamurixilonin.pdfIn PDF document text
    • http://www.sealjet.mn/pictures/files/3876314996.pdfIn PDF document text
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/e3udrfjqi5km3h11a862hvmrs9/92581773148.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/160fa7fdeb2e9e---vipomudarivovosonofojemi.pdfIn PDF document text
    • https://szaniterplaza.hu/ckfinder/userfiles/files/9308861330.pdfIn PDF document text
    • https://cristiandellavedova.com/wp-content/plugins/super-forms/uploads/php/files/vv5puha18vcns7ttoust259ms3/konafesuwepefavoselalubem.pdfIn PDF document text
    • http://joewhitefamilysite.com/clients/59967/File/47263850016.pdfIn PDF document text
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/983b0f081be12aa795119efb16f0bb37/67763027626.pdfIn PDF document text
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a15858358ef---92808008005.pdfIn PDF document text
    • https://kildevangen.dk/files/27143235736.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=libro+de+historia+savia+2+secundaria+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_off0000c6cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6CC 17820 bytes
SHA-256: 176cd2f8bb507602ee58def9099b7a280c84dd1d32104c42bc21d931fda2b793
font_01_sfnt_off0000f437.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF437 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010c4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C4E 11056 bytes
SHA-256: e59c7df5959037c124abc4b85e4e72e4ded2665e2a08c4dd888546835b7da6da

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