Malicious PDF — malware analysis report

Static analysis result for SHA-256 52efdd4de1d253dd…

MALICIOUS

PDF

79.0 KB Created: 2021-09-19 19:47:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 97b052bf37d14397d92d6314bad80f18 SHA-1: 528702504021e095286a33db6ea81ed411b4c3a2 SHA-256: 52efdd4de1d253dd33d77514905c19ad888ac7e038bc0256e0c4a4f445d726c6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm directing to multiple domains, several of which are hosted on compromised CMS platforms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. No scripts were extracted, and the document body was unreadable, limiting further analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • 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.
  • 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 http://szymonadamczyk.pl/uploads/fck/file/21760793545.pdf In PDF document text
    • http://giadinhlaurenso.org/upload/files/68067359886.pdfIn PDF document text
    • http://chistogood.ru/admin/ckfinder/userfiles/files/46718755928.pdfIn PDF document text
    • http://newgatedesign.com/Images_upload/files/67769529239.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141161d5902f---85569606179.pdfIn PDF document text
    • http://www.cda.org.hk/ckfinder/userfiles/files/24575098520.pdfIn PDF document text
    • http://dush-kz.ru/uploads/fck/file/79273038212.pdfIn PDF document text
    • http://studiobaliva.eu/userfiles/files/nalajenuveb.pdfIn PDF document text
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/5de70f98e2ec5f07eb439dae446e955d/doseragajepegodo.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161416618c580c---11226259906.pdfIn PDF document text
    • https://goldenlinejsc.com/userfiles/file/luvaxovufobezug.pdfIn PDF document text
    • http://www.og2c.com/images/file/12422732150.pdfIn PDF document text
    • http://salespate.com/userfiles/file/67345444656.pdfIn PDF document text
    • http://tianfonmm.com/d/files/demop.pdfIn PDF document text
    • http://partnercable.com/files/61950912426.pdfIn PDF document text
    • http://liebherr-tr.com/userfiles/file/mebopurawugoke.pdfIn PDF document text
    • http://architettotamborra.eu/userfiles/files/juvaruj.pdfIn PDF document text
    • https://tonthephunglan.vn/upload/files/48588328348.pdfIn PDF document text
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fc1cc9ff98---89093371459.pdfIn PDF document text
    • https://abctranslink.com/ckfinder/userfiles/files/woxapesunorerik.pdfIn PDF document text
    • https://reklama71.ru/upload_picture/rufowiwojon.pdfIn PDF document text
    • http://0575zl.com/userfiles/file/37084131948.pdfIn PDF document text
    • http://dayuntang.com/assets/uploads/ckedit/files/20210902020923.pdfIn PDF document text
    • http://fusiongrup.ro/userfiles/file/9433509034.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=how+to+get+vola+sports+on+firestickPDF 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_off0000cdc2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDC2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e5d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5D4 18160 bytes
SHA-256: 05b429a64f1bbe077de7a548fbb174187be7b86d7535fa0fbbbe8814f1c355bd
font_02_sfnt_off00011484.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11484 10888 bytes
SHA-256: 1c76b4892e0e96b185d6ae462175413799457d40719db7b4d3642e02a2d72899