Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c9808453c69bb56…

MALICIOUS

PDF

73.9 KB Created: 2021-09-08 19:05:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 3b16e6df3eae6f6be94fff00236f0b3b SHA-1: d477b541fdf01ea77b7f65390619b6e7558de1de SHA-256: 4c9808453c69bb56affce5d1ba1add2922e7bc010064d004fabd0c312ce0ff45
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to obscure the ultimate destination. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites.

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://rougezenekar.hu/files/file/42242503888.pdf In PDF document text
    • http://rc-modeller.se/images/file///51240617268.pdfIn PDF document text
    • http://celeb.huh.hu/UserFiles/File/roxokexorek.pdfIn PDF document text
    • https://chogmai.org/ckfinder/userfiles/files/ruvavufizis.pdfIn PDF document text
    • http://shbaicun.com/userfiles/file/2021090707072973499.pdfIn PDF document text
    • http://semihkerpiccilervesupersound.com/upload/file/2063763653.pdfIn PDF document text
    • http://lyzph.com/userfiles/file/Fl202109032245193079.pdfIn PDF document text
    • http://alrabbanoilandgas.com/file/files/sujipik.pdfIn PDF document text
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161387a0a13453---26400164357.pdfIn PDF document text
    • https://www.andimoda.com/wp-content/plugins/super-forms/uploads/php/files/bffcd39395c395bb16c6f76ac3211539/43535411784.pdfIn PDF document text
    • http://gzsjlt.cn/userfiles/file/gimonolasuregadebazerasog.pdfIn PDF document text
    • http://meditopthailand.com/file/wofigikiwanukabisifigos.pdfIn PDF document text
    • http://kukubara.com/zdjecia/file/rawewuxunomanuwexegob.pdfIn PDF document text
    • https://xn--fct8ml6mwue.tw/uploads/files/22771267511.pdfIn PDF document text
    • http://forti.in/userfiles/file/zagujujuverawivotutafiz.pdfIn PDF document text
    • http://colorfusion.us/admin/images/file/27553375810.pdfIn PDF document text
    • http://degeninhotel.ru/admin/ckfinder/userfiles/files/29650835153.pdfIn PDF document text
    • https://toskov-yordanov.com/userfiles/file/31640450446.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/4c9e2dd9bdb000888bb8238bca44868b/27113957012.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/nfa686vmshq3a1mn4ahls0gif5/26406993774.pdfIn PDF document text
    • https://queensflower.nl/clientfiles/jopokivupinenezo.pdfIn PDF document text
    • http://immobiliareborghi.com/userfiles/files/86381392706.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1613123d098e30---77668712875.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=mazda+mpv+2006+repair+manualPDF 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_off0000be42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE42 16380 bytes
SHA-256: 9571e2d0f866cbb9ba75338ade111fd06d70988dfa506b78afb4043adddb7329
font_01_sfnt_off0000e8b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8B2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000100c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100C9 10796 bytes
SHA-256: dea9ebec76d73c3b2ae8aa393310992b49e5e36be82bccc19267308714c11c86