Malicious PDF — malware analysis report

Static analysis result for SHA-256 ecd13fdccdc9d88d…

MALICIOUS

PDF

68.1 KB Created: 2021-03-13 22:45:38 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-18
MD5: d06f2e3f5812100aeed4c3f558187b92 SHA-1: efe75a4ae6308e2653c3d427d889595716d461e2 SHA-256: ecd13fdccdc9d88d5417f4ed93df9a016aabff27c982dedce628a914e4c714c9
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of external links pointing to various PDF documents hosted on disposable domains, as indicated by the PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO spam. The embedded URLs and the nature of the link farm point towards an attempt to manipulate search engine rankings or distribute further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://dugedepap.ru/award?keyword=razones+trigonometricas+de+angulos+suplementarios+ejercicios+resueltos+pdf PDF link annotation
    • https://cdn.sqhk.co/mujawiru/QgjZigt/3318630078.pdfIn PDF document text
    • http://hempmap.ru/rumatosijojegivjf5nn.pdfIn PDF document text
    • https://cdn.sqhk.co/dedomafub/f6hovhf/turn_off_roaming_on_samsung_gt_s5230.pdfIn PDF document text
    • http://startbastar.online/can_t_help_falling_in_love_kalimba_tabss40f9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420743/normal_5fdc67e94e15c.pdfIn PDF document text
    • http://uscreditmonitoring.info/13_original_colonies_map_worksheetc920q.pdfIn PDF document text
    • http://kenugizi.getenjoyment.net/thermador_range_error_code_e6100.pdfIn PDF document text
    • https://cdn.sqhk.co/lawipavoso/gd46hfE/retiruzomevopaledixina.pdfIn PDF document text
    • http://newuwedeza.mypressonline.com/37601682279.pdfIn PDF document text
    • http://miwuzobi.sportsontheweb.net/42724218906.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4500446/normal_5ffd2af20da14.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://d3dd75b0-514a-4dbf-a1f7-973a5b421fb1.filesusr.com/ugd/5b46ec_e697a657aadc4c5f851e936b3fce63cc.pdf?index=trueIn PDF document text
    • https://6d4a8fb0-9a8a-4850-8aa1-2b5706121c9a.filesusr.com/ugd/ff2e72_1255e84e97c346dc86d22e32fde6ce5c.pdf?index=trueIn PDF document text
    • https://c4cd0dbc-23d7-4f11-b65f-2561cec8abe5.filesusr.com/ugd/516793_1ba2622a44a347bb80da2e612d0d7e94.pdf?index=trueIn PDF document text
    • https://8860adff-7f0b-4cf3-a358-cdd560dff136.filesusr.com/ugd/625844_bc43e105fc69488d9031e5e7ed6628db.pdf?index=trueIn PDF document text
    • https://edefa294-c65c-46c5-840b-8a4669b9fdfe.filesusr.com/ugd/e4a001_81363d41086042d6aa78e8311b2773b1.pdf?index=trueIn PDF document text
    • https://a181bb3e-7445-4f1f-a1cf-b2fe66c13e92.filesusr.com/ugd/91ce54_403d1c8c24fc4c91accc07b3be2dcd8a.pdf?index=trueIn PDF document text
    • https://2f8a6ab9-e864-4757-b083-6627a13f4c48.filesusr.com/ugd/405339_53d80b29811447e68d1b70a803540f82.pdf?index=trueIn PDF document text
    • https://7a3463bf-3117-47cc-940f-ad9d50d05675.filesusr.com/ugd/9f2514_33cc8bf5443c46ae98b4e6ab2750098b.pdf?index=trueIn PDF document text
    • https://356bbf58-84af-4bff-99a9-d03346e46411.filesusr.com/ugd/b5472a_043648cd7d33482e96e032cb6c2c523b.pdf?index=trueIn PDF document text
    • https://ecf8b3bd-8201-449f-a39c-156acd88681e.filesusr.com/ugd/97634b_786379e72cff497e9e8c951136d5098b.pdf?index=trueIn 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_off0000d01f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD01F 5608 bytes
SHA-256: 2593d8be5acb525e585e13c29a2562fe940fef5ea766748dc0faacac62ab2573
font_01_sfnt_off0000e332.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE332 11796 bytes
SHA-256: 1db1354774b2c3bccf3e8e42180203e96d762f7543008989fbf0d49cafefb85b