Malicious PDF — malware analysis report

Static analysis result for SHA-256 af8da087a7ac11b3…

MALICIOUS

PDF

93.7 KB Created: 2021-09-08 00:58:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: a5633323f4843f41a75df050d7484002 SHA-1: ac063111288481ad17269343eb5456573accc0e5 SHA-256: af8da087a7ac11b330af10e5123a3846679f4dfa84552e0b4b6f42fb6df4932d
156 Risk Score

Malware Insights

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

The PDF contains a large number of links pointing to various websites, many of which are hosted on compromised WordPress installations or disposable domains. This structure suggests the document is intended to act as a link farm, likely to distribute phishing content or malware. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 http://olddieselparts.com/ckfinder/userfiles/files/denugodegiwugijivup.pdf In PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160847cacebd60---64912339524.pdfIn PDF document text
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/q4r9msrveevj4dm1b714kbsoqp/88888024815.pdfIn PDF document text
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/e0056e76927e5ab3494f06d0f3dda51f/tisopujamixiruwozubume.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092f7674e5eb---56501251047.pdfIn PDF document text
    • http://fabrykakonwersji.pl/wp-content/plugins/super-forms/uploads/php/files/cc879bbe8841353819e66f53c5e29046/wijupujanukaj.pdfIn PDF document text
    • http://jamessham.com/admin/usercontent/file/30326633349.pdfIn PDF document text
    • http://matsonconstruction.net/userfiles/file/koterezikudobapivexe.pdfIn PDF document text
    • http://bjhtdszdh.com/v15/Upload/file/202152178493136.pdfIn PDF document text
    • http://ok-poland.com/userfiles/file/gipifetirilenafitavapa.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609784f198163---84753843413.pdfIn PDF document text
    • http://losmarinoslanzarote.com/marinarubicon/admin/file/rudegafimijazivewital.pdfIn PDF document text
    • http://studiotecnicoforace.eu/userfiles/files/bezobapamavekedopanidaz.pdfIn PDF document text
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/1608536464f41d---89320149652.pdfIn PDF document text
    • http://tmkb.org.tr/ckfinder/userfiles/files/225933401.pdfIn PDF document text
    • http://allaboutdowney.com/userimages/pozoxedesutomiwo.pdfIn PDF document text
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/7a44d7f99a725a832a9b0fb9e2fe5fae/3037477892.pdfIn PDF document text
    • http://yongqingtech.com/d/files/xuzuwufebabeto.pdfIn PDF document text
    • https://southtours.com/wp-content/plugins/super-forms/uploads/php/files/q5op6retjkungjlu33vl9v56b0/lesagixenununitalotupa.pdfIn PDF document text
    • https://lesura.net/userfiles/file/lotaveluvalusavez.pdfIn PDF document text
    • https://kaktutzhit.by/uploads/files/jarupoburunafefute.pdfIn PDF document text
    • http://dmhu.eu/uploads/uplib/file/katelatuwe.pdfIn PDF document text
    • http://jointrilogy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074d8ed85a43---relefadugujobelosimomat.pdfIn PDF document text
    • https://innovaciones-plasticas.com/imagenes_cont/sitio/documentos/nanoden.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=sample+balance+sheet+for+small+business+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_off00010652.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10652 18908 bytes
SHA-256: c9e2e131b47f422f3baac5ce3e57b86941ce13e22330986de1db5f087f3fb676
font_01_sfnt_off00013728.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13728 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014f3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14F3F 11200 bytes
SHA-256: b9fc456c4f68c6e24729768b57171021400f9bf227c605ec00a76afdc0b4ef27