Malicious PDF — malware analysis report

Static analysis result for SHA-256 641d9698d9f378dc…

MALICIOUS

PDF

78.6 KB Created: 2021-09-06 03:57:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: cb474369f2a2325a928e8382d8f4f647 SHA-1: 9a72813a9d4b5256e7b21fe2871a8aa5038cb53d SHA-256: 641d9698d9f378dcafeba55e75ee02a8e6152a06bd2482732fcb4727905d91f2
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains heuristics indicating it is a link farm and a fake invoice lure, suggesting it's designed to trick users into downloading malicious files. The ML classifier and ClamAV detection strongly indicate malicious intent. Although no scripts were explicitly extracted, the structure and URL patterns are consistent with a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 7

  • 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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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://www.notusweb.com.br/ckeditor/ckfinder/userfiles/files/96754338729.pdf
    • http://atomiccm.com/userfiles/files/55725264883.pdf
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/e8c941fb947c2f8d5a15c412c9d67c80/67354892674.pdf
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/fdi32j4bbsno83sqo95hj7e1q5/zururu.pdf
    • http://hsiwww.com/image/files/20210724_055944.pdf
    • https://ijmscr.com/ckfinder/userfiles/files/74538294199.pdf
    • https://webmenuplus.com/images/file/rojegekipofid.pdf
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/2dd04bdaf11ceb15dd9a962f78060375/ruxal.pdf
    • https://www.dartmusicfestival.co.uk/wp-content/plugins/super-forms/uploads/php/files/778e3c77a97da9735efe4e19a8146365/jupitebizofuvexolifiziven.pdf
    • http://www.mediacomriccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/160ad6d6b251b3---foropetoxidigetimet.pdf
    • http://xn--939a66v0zjo3bcvdmrp.com/data/ckfinder/files/panugasitu.pdf
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a41e9711fe7---ruboti.pdf
    • http://leaders-adv.net/userfiles/file/nidorifuw.pdf
    • https://bititechnika.com/uploads/file/43973220585.pdf
    • http://vector-luczak.pl/new/fck_user_files/file/bopasopanasurilodesede.pdf
    • https://taybaite.com/userfiles/file/nadedekopuporukanovi.pdf
    • http://mikomisushiwc.com/uploads/files/13586312025.pdf
    • https://mimpidia.com/contents//files/77529831806.pdf
    • http://legalinet.eu/userfiles/files/mawefimuja.pdf
    • http://clubselectionvoyages.net/images/file/7102992780.pdf
    • https://janeunchained.com/wp-content/plugins/super-forms/uploads/php/files/dvc83e1up24bluji517qrcdajh/dulivipanuwasufaguxuta.pdf
    • http://korvet-sp.ru/userfiles/file/9521204745.pdf
    • https://bobecoingatlan.com/uploads/editor/file/vuxokawutuja.pdf
    • http://cu-hinothai.com/ckfinder/userfiles/files/nukerowezubefube.pdf
    • http://sskj.pl/userfiles/file/10559957426.pdf
    • https://bataretak.com/img/files/file/zilazip.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=gst+proforma+invoice+format+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cfea.bin
ffc6d04721704ea2c2cbd06f5cd840711791d3c0f31dea3df7e139cab26f3127
pdf-font-stream PDF embedded font (sfnt) at offset 0xCFEA 16808 bytes
font_01_sfnt_off0000fb1b.bin
fc420b1611e96680f1a9e4acbb7056e02903b8c2a1e85cb18f3c734cebf37be5
pdf-font-stream PDF embedded font (sfnt) at offset 0xFB1B 10840 bytes
font_02_sfnt_off00011430.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11430 16792 bytes