Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8087e4d0ddc067f…

MALICIOUS

PDF

71.0 KB Created: 2021-09-15 11:34:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 535ac28f3315ace43233461017b5713e SHA-1: 0aa0e3c1f64c4811f73295dc1c8f1ba5efd8abfa SHA-256: b8087e4d0ddc067fcd7fd71e0ca58c0b671259cb2428f1962f58e7c6fb5e85e3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs pointing to various domains, many of which are hosted on compromised CMS platforms or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://www.bmo-agencement.fr/ckfinder/userfiles/files/48695473764.pdf In PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141aded2ac04---nokusutirezexobude.pdfIn PDF document text
    • http://77owship.netsociality.com/upload/files/6773042887.pdfIn PDF document text
    • https://www.andimoda.com/wp-content/plugins/super-forms/uploads/php/files/499d6a8fcfe3dcf357a6496fe317ac8d/81912760797.pdfIn PDF document text
    • https://energiadirect.pl/application/resources/ckfinder/userfiles/files/9652185008.pdfIn PDF document text
    • http://www.ecvbrass.ch/user/web/file/84080490248.pdfIn PDF document text
    • http://domki-kopalino.pl/pliki/sotorivurufagikorubexutev.pdfIn PDF document text
    • http://ebiocell.com/uploadfile/file///2021090310112359.pdfIn PDF document text
    • https://asiantms.com/ckfinder/userfiles/files/26856970238.pdfIn PDF document text
    • https://kalimati.in/userfiles/file/tuposonazegamatu.pdfIn PDF document text
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/161404d7233925---49102412982.pdfIn PDF document text
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/773cc5fe7eec28c4896ba494fb52fa4d/ruzizefogilumof.pdfIn PDF document text
    • http://gomsuhoangminh.com/app/webroot/uploads/files/bojepizolu.pdfIn PDF document text
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/d81280293ca9092cd144b7d152329a1c/kiliw.pdfIn PDF document text
    • http://tajilin.com/upload/files/50405913276.pdfIn PDF document text
    • http://vladjurnalist.ru/archive/file/xijobir.pdfIn PDF document text
    • http://ceskylakros.cz/userfiles/file/rugosumutexukozoxe.pdfIn PDF document text
    • https://telorgabus.com/contents/files/9500367133.pdfIn PDF document text
    • http://tainghe.vn/userfiles/file/rumeduzefipanuse.pdfIn PDF document text
    • http://aktifithalat.com/resimlerfiles/widosediko.pdfIn PDF document text
    • http://ballmillfactory.com/d/files/17552681752.pdfIn PDF document text
    • http://solamsys.com/userData/board/file/83251415769.pdfIn PDF document text
    • http://gsnursing.in/ckeditor/ckfinder/userfiles/files/49214622119.pdfIn PDF document text
    • http://massimosusto.eu/userfiles/files/takesedisoditeminat.pdfIn PDF document text
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/855572081a0f556dea8b52cab7c98d7e/soxumavarodupolozoki.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=boku+no+hero+academia+5th+season+1PDF 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_off0000b50c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB50C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cd1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD1E 15528 bytes
SHA-256: 6eb19589b167603a7209ced51b1c5052e79bba4a208b0cac3da9f53e321b10a9
font_02_sfnt_off0000f472.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF472 11020 bytes
SHA-256: 1e0eba5fe02627303ac2260809aa83c193efa9eeb7a425a72cbaa26a71892d16