Malicious PDF — malware analysis report

Static analysis result for SHA-256 777621a6842ca366…

MALICIOUS

PDF

75.8 KB Created: 2021-09-17 10:21:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 0bc03707039ee575b70a40810af8a859 SHA-1: 4ed98e2dbe0cdade32b776d5efcca4cc585217cd SHA-256: 777621a6842ca3663dabfaa94919cc0bbc71f6ec76e3546e5dc13f20a1ff7dc0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised or disposable domains, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs are consistent with techniques used to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143f990a5d7d---34052974633.pdf In PDF document text
    • http://analhospital.net/file/files/6212704542.pdfIn PDF document text
    • https://argekaucuk.com/nbg/upload/files/gukusukubaj.pdfIn PDF document text
    • http://chandravanshi.com/userfiles/file/90648901677.pdfIn PDF document text
    • https://dallaslandscapedesign.com/media/files/12910139525.pdfIn PDF document text
    • https://regenerateacademy.com/file/41844301868.pdfIn PDF document text
    • http://think6.net/ckfinder/userfiles/files/20210914092517.pdfIn PDF document text
    • http://capitaldanceacademy.com/userfiles/files/gofexukupuk.pdfIn PDF document text
    • https://ozora.schaffsen.com/contents/file/20156964963.pdfIn PDF document text
    • https://kfmaccounting.com/webroot/img/content/files/boravoku.pdfIn PDF document text
    • http://quatanggiabao.com/images/uploads/files/zenobozodafejumuw.pdfIn PDF document text
    • https://www.htlexpress.com/ckfinder/userfiles/files/kusomu.pdfIn PDF document text
    • https://123natura.com/stockages/files/nulawinub.pdfIn PDF document text
    • http://www.binghan.my/userfiles/file/fiwizogarikurume.pdfIn PDF document text
    • https://k-newsletter.com/ckupload/files/43598471136.pdfIn PDF document text
    • http://softwaretesting.kr/club/data/userfiles/file/20210901161104.pdfIn PDF document text
    • http://rubensova16.cz/files/file/jemogavegivuwejerufid.pdfIn PDF document text
    • http://kocavietnam.com/upload/files/85806674513.pdfIn PDF document text
    • https://jasmijnbloemengroen.nl/userfiles/file/76012213906.pdfIn PDF document text
    • https://mgs-on-track.com/uploads/misc/files/rubaxesi.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/16133be478543f---78573213652.pdfIn PDF document text
    • https://jhservice.net/imagenes/galeria/files/nolawanezoxixonapuvogedi.pdfIn PDF document text
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/16142fac0e81e0---41883247522.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=percy+jackson+book+2+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_off0000c332.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC332 10976 bytes
SHA-256: 14753fe55b336ec14563971ba7452e7abb77353595b6a0dae5149cfbcb95be9d
font_01_sfnt_off0000dcad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCAD 17268 bytes
SHA-256: c1b4827d9442d30653a61859e63056730650f748b2988f39a057a8496e099ecb
font_02_sfnt_off00010971.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10971 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1