Malicious PDF — malware analysis report

Static analysis result for SHA-256 41bdbb601e1b8f81…

MALICIOUS

PDF

76.9 KB Created: 2021-09-23 09:09:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 5e56e2e0c7b4cc50fc82fd2ee5507be5 SHA-1: 88b13158effc8dca3c3ad711569ad970481a858b SHA-256: 41bdbb601e1b8f81e94dd4740bf65c8c3c2b17794d55b5611b1cb1196e618d8b
156 Risk Score

Malware Insights

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

The PDF contains multiple links pointing to compromised CMS uploads and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The embedded URLs, particularly those on compromised WordPress sites, are the primary indicators of this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/prkg9gojlp1hgv253cmc69mcah/80538369609.pdf In PDF document text
    • http://suurelepa.ee/data/file/60518513758.pdfIn PDF document text
    • http://tincorner.vn/uploads/files/susujopozorus.pdfIn PDF document text
    • http://bestpokeya.com/uploads/files/50722759015.pdfIn PDF document text
    • https://gppacdatabase.net/userfiles/file/82506022873.pdfIn PDF document text
    • https://marblobathware.com/app/webroot/img/files/74467541630.pdfIn PDF document text
    • https://pastijptoto.com/contents/files/89045182892.pdfIn PDF document text
    • http://kusistoconstruction.com/userfiles/file/voziroxagopekovana.pdfIn PDF document text
    • https://officialbacknumber.org/editor_up/babixuraporidosuxewabe.pdfIn PDF document text
    • http://rhondachem.com/d/files/34284148115.pdfIn PDF document text
    • http://firesecurity.sk/userfiles/file/wezitefoliwewewevuxupazo.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613d8ad4db163---15603711874.pdfIn PDF document text
    • http://greatnice.club/updatefiles/file/gidevu.pdfIn PDF document text
    • https://caribemed.com/userfiles/file/voloxebigutaxalejojiz.pdfIn PDF document text
    • https://vmwarts.com/ecovic/file/17479753937.pdfIn PDF document text
    • http://dkstores.gr/userfiles/file/sopigekurobifun.pdfIn PDF document text
    • http://webinaris.blog/ckfinder/userfiles/publics/files/gitagerojobepubokexekag.pdfIn PDF document text
    • http://dmkert.hu/files/file/felinijoruzikediv.pdfIn PDF document text
    • https://shieldtech.cz/ckfinder/userfiles/files/61884341130.pdfIn PDF document text
    • https://serviceelectric.ca/userfiles/file/rafodazawonusa.pdfIn PDF document text
    • http://nuraski.pl/wsg/userfiles/bojojivekinitimol.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16139e9bf5f170---zijaparojupenuzu.pdfIn PDF document text
    • http://orkoien.com/userfiles/files/7742943151.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/pj56msi9c8bm6l9ibsfnlgprpj/40808235552.pdfIn PDF document text
    • http://gardens-spa.com/user_pict/file/tajiteb.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=samsung+whistle+download+for+androidPDF 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_off0000c6d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6D3 11060 bytes
SHA-256: 63e75b00b7b6e12d1853e21f7206bb73469abfd85436e837439be02a630cc72a
font_01_sfnt_off0000e032.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE032 17824 bytes
SHA-256: 15358261849807407e32b9b426924a7233390e83dbe581c44b5a7ea754b956c8
font_02_sfnt_off00010de3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DE3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1