Malicious PDF — malware analysis report

Static analysis result for SHA-256 d31af4e0d77d30d7…

MALICIOUS

PDF

78.4 KB Created: 2021-09-18 19:30:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 8076632f6d26a7aa4aacec7425c44938 SHA-1: ba6b0c7b143cdef478ca49ab75d7420dd4c98407 SHA-256: d31af4e0d77d30d7630ccedb9dfc4c0a78c81b19bf44066b962ff6821be33edc
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML and ClamAV as malicious, with heuristics indicating it functions as a link farm on disposable hosting. Numerous embedded URLs point to potentially malicious sites, suggesting a phishing or malware distribution scheme. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with common PDF-based attack vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://alice-immo.com/userfiles/file/bojopirun.pdf In PDF document text
    • http://bebsulmare.com/userfiles/files/jevofafevuta.pdfIn PDF document text
    • http://puntolinea.org/userfiles/files/13030731325.pdfIn PDF document text
    • http://hastensandbreakfast.nl/userfiles/file/xasavikikaru.pdfIn PDF document text
    • http://tianfonmm.com/d/files/kalodugizavit.pdfIn PDF document text
    • http://eros-arena.com/eros/userfiles/file/mesejasajodafalapeve.pdfIn PDF document text
    • https://www.willmarshelter.com/ckfinder/userfiles/files/duwavunijamodanujiruguw.pdfIn PDF document text
    • https://treasurehunterdetectors.com/ckfinder/userfiles/files/sibaxolizabizezatojusumiv.pdfIn PDF document text
    • http://jsqnchem.com/upload/files/80182238782.pdfIn PDF document text
    • http://memsports.com.br/admin/libs/ckeditor/ckfinder/files/18013862782.pdfIn PDF document text
    • https://mimpishio2.com/contents/files/74855449740.pdfIn PDF document text
    • https://dildendilecevirievi.com/upload/ckfinder/files/51406574034.pdfIn PDF document text
    • http://elma1.ru/!upload/files/57404526747.pdfIn PDF document text
    • https://akilanews.com/ckfinder/userfiles/files/1279559255.pdfIn PDF document text
    • https://pointswestliving.com/ckfinder/userfiles/files/66352847557.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d364330134---40394191881.pdfIn PDF document text
    • http://denda.co.kr/ckfinder/userfiles/files/tonujabu.pdfIn PDF document text
    • http://cleanyachts.it/writable/public/userfiles/file/77559181452.pdfIn PDF document text
    • http://1night2day.com/ckupload/files/98323809475.pdfIn PDF document text
    • https://biodent.ro/m4fm_files/m4news/ck-uploads-files/82517300442.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1614502076b959---bedodeduji.pdfIn PDF document text
    • http://jjburgerut.com/uploads/files/94705299148.pdfIn PDF document text
    • http://topflexsports.com/uploads/zekodi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=fortnite+christmas+free+skinsPDF 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_off0000cf4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF4A 10624 bytes
SHA-256: b13ad4cfaedcaa31ed402ec7f5610b1c6ac04af91457bc0080c12100b2c57218
font_01_sfnt_off0000e766.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE766 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ff78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF78 17240 bytes
SHA-256: 220a18b90ed3461f5e147daa6ef4bbf09b042d53f5fd7c731df5e0b6c701f23f