Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f891803917355db…

MALICIOUS

PDF

73.1 KB Created: 2021-09-02 06:35:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 1665000e583641c8226f09b25921d268 SHA-1: c5d509e4d522dbc1675f38d415f78e3d369a56ef SHA-256: 4f891803917355db1ecacf41688e6a12c3fdab34140358df1766e49b4fa9e314
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

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://krisoc.ru/uplcv?utm_term=another+word+for+not+only+but+also PDF link annotation
    • http://2990592.ru/ckfinder/userfiles/files/5353645967.pdfIn PDF document text
    • http://bamt.be/wp-content/plugins/formcraft/file-upload/server/content/files/160948a7381c4a---49765047341.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cd79c465340---91194359575.pdfIn PDF document text
    • http://4yoga.by/pics/files/25404166058.pdfIn PDF document text
    • https://gulf-rope.com/images/bulk_images/files/jesuzizekob.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609fa657dbc0d---3403184710.pdfIn PDF document text
    • http://gdwtechnology.com/fckeditor/file/fusukorazolizum.pdfIn PDF document text
    • http://licausi.it/userfiles/files/damukarivonuj.pdfIn PDF document text
    • http://nutricion-intravenosa.com/wp-content/plugins/super-forms/uploads/php/files/0d0fe0f4975eef9a8347a094555c83f8/bomubibagukezozimazizu.pdfIn PDF document text
    • http://epodhajska.eu/UserFiles/File/gavupomawa.pdfIn PDF document text
    • http://cecev.com/stockages/files/98669654763.pdfIn PDF document text
    • https://webtraffic.ch/wp-content/plugins/super-forms/uploads/php/files/lt9i9h2nu5lnqub3aosa3bm0ck/33069835246.pdfIn PDF document text
    • https://kindliving.org/wp-content/plugins/super-forms/uploads/php/files/tmp/12433776169.pdfIn PDF document text
    • https://tongdaidoanhnghiep.com/app/webroot/upload/files/61634095507.pdfIn PDF document text
    • https://autoprofi.ua/userfiles/file/mesalidovodelug.pdfIn PDF document text
    • https://mimpishio2bet.com/contents//files/lovabal.pdfIn PDF document text
    • https://vydavatelstvoklett.sk/userfiles/file/7931296843.pdfIn PDF document text
    • https://fuchscars.com/wp-content/plugins/super-forms/uploads/php/files/bf729f05138ae370c8357753358bae6e/44336806246.pdfIn PDF document text
    • https://vegan-eshop.cz/data/file/dokizafujedozufuxodegep.pdfIn PDF document text
    • http://cokhibaosang.com/media/ftp/file/24727232294.pdfIn PDF document text
    • http://arcos-eff.it/userfiles/files/gunofexiro.pdfIn PDF document text
    • https://hoangvan.vn/wp-content/uploads/files/58705265022.pdfIn PDF document text
    • http://www.chatanakonci.cz/userfiles/file/lopesebatifutujuxaregana.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16074a65c71dcc---59907335918.pdfIn PDF document text
    • http://tsradviseurs.nl/mailing/images/photo/file/fedupowaxagaliwopef.pdfIn PDF document text
    • 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_off0000bc76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC76 10780 bytes
SHA-256: a78e51257dce2100bfe5ffbc6971231ea14401064587b682535bb126ef9c4aa4
font_01_sfnt_off0000d553.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD553 16100 bytes
SHA-256: 329b3747ec6636f021c5f5168824246f37dbd97b6507071aee946103b428f51c
font_02_sfnt_off0000fe4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE4C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1