Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d4280c80e0955f2…

MALICIOUS

PDF

65.8 KB Created: 2021-06-11 02:43:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: a81fef27da1c3bed51fa818908bb38d7 SHA-1: 2482ff9f9f6e53fa0641185cbbc82e6ff787b447 SHA-256: 4d4280c80e0955f23400823f43acf7ac2e40fb42099db78fd18a31085e037bd1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF document contains numerous embedded URLs that form a link farm, with many pointing to compromised WordPress upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and URL patterns are indicative of a malicious document designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://krisoc.ru/uplcv?utm_term=zinitevi+movies+%2526+tv+show PDF link annotation
    • http://chronocertif.com/userfiles/file/kimikewomupem.pdfIn PDF document text
    • https://jxloanchien.com/style/postimage/file/jajupunap.pdfIn PDF document text
    • https://markeishahall.com/wp-content/plugins/super-forms/uploads/php/files/90ed4ac1bbd88bfdc52471c11a1d447f/dajizidezivumofuk.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/2af69a2d1064e41909d06994ea1e1831/mosuk.pdfIn PDF document text
    • https://kindliving.org/wp-content/plugins/super-forms/uploads/php/files/tmp/34027215481.pdfIn PDF document text
    • http://bochosushi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080124625088---7641619530.pdfIn PDF document text
    • https://thejinglelab.com/wp-content/plugins/super-forms/uploads/php/files/82fccbua0u89snqrin31h2j0d8/64114738177.pdfIn PDF document text
    • http://ibb-online.ru/f/file/76695984757.pdfIn PDF document text
    • https://useoneconvo.com/wp-content/plugins/super-forms/uploads/php/files/1bc66970fe3ec35815c5d8b03023ea71/12150912178.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af9493812a7---wuzinerulivuzofamo.pdfIn PDF document text
    • http://piqiso.ru/userfiles/file/kodewoko.pdfIn PDF document text
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/57a07a0e82968ad7beec908a4d1c6dec/kutuzifagufesomawol.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/qhs5u84ho9vf3fv6rap9a38ulp/72972959071.pdfIn PDF document text
    • http://trenermichal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1608b2a832e6ee---reboj.pdfIn PDF document text
    • http://studiodabo.eu/userfiles/files/43772060853.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c961.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC961 4508 bytes
SHA-256: 1d6ec9d712700521e841a4baff26b6261a92e55b84e8f907b1a8fea0c66a01e2
font_01_sfnt_off0000d8b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8B1 9936 bytes
SHA-256: 9e1000a52c4962818ab557a1ab8832846338c8a1a7fed382792a2b0e1cb748a2