Malicious PDF — malware analysis report

Static analysis result for SHA-256 b51efc0f6dc3401b…

MALICIOUS

PDF

75.1 KB Created: 2021-09-15 21:33:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b1d03b82af203ef7e953aa87a8080e16 SHA-1: 2184ffb5f09ad9fccfcc967676182b60cecfed15 SHA-256: b51efc0f6dc3401b1642e2588c379024e547caedc21600ea2d075162362df1d5
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. It contains numerous embedded URLs, many of which point to potentially disposable domains and are structured as link farms, suggesting a phishing or malware distribution scheme. While 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 0.9973

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 http://studioguidobarbieri.it/userfiles/files/bakutijijomofefokipot.pdf In PDF document text
    • http://jsdarvin.com/files/94877388565.pdfIn PDF document text
    • http://ilyxrace.com/userfiles/files/21307448842.pdfIn PDF document text
    • http://tetraeng.it/userfiles/files/lususoxizosexebedojikizoz.pdfIn PDF document text
    • http://nayyaralidada.com/alpha/ckfinder/userfiles/files/41468153021.pdfIn PDF document text
    • https://dijitalsanat.link/upload/files/56870346935.pdfIn PDF document text
    • https://rumusjitu.com/contents/files/libavon.pdfIn PDF document text
    • https://pleasanton.com/wysiwygfiles/file/68319977219.pdfIn PDF document text
    • http://mrpokedb.com/uploads/files/situtivegopijibu.pdfIn PDF document text
    • http://mazdooradda.com/userfiles/file/64919000838.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/zewejanuxiveseka.pdfIn PDF document text
    • http://forglass.sk/userfiles/file/lagaluzajofujosi.pdfIn PDF document text
    • http://cmorshomecareassociates.org/uploaded_files/userfiles/files/gokodimexizovas.pdfIn PDF document text
    • https://avela.md/userfiles/file/munagogezirugun.pdfIn PDF document text
    • http://agilesolutions.in/uploads/fofugadoxobalilikezavimi.pdfIn PDF document text
    • http://sushimura1.com/uploads/files/kukonikugabuxatoz.pdfIn PDF document text
    • https://triosms.com/userfiles/file/47526465470.pdfIn PDF document text
    • https://kaparatt.com/images/File/6379656434.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/6q9he7n3jn925md88gr6ggbn1j/64648583525.pdfIn PDF document text
    • http://www.petersonassoc.com/emailimages/file/wapiketobig.pdfIn PDF document text
    • https://nibrasimansch.com/userfiles/files/96243823253.pdfIn PDF document text
    • http://bimbrlata.cz/UserFiles/File/venivomino.pdfIn PDF document text
    • http://bhhangkhong.com/upload/images/files/79237076182.pdfIn PDF document text
    • http://cosmoscm.com/contents/files/vuxuz.pdfIn PDF document text
    • https://proektasis.gr/admin/spaw2/uploads/files/vakukopusofozumomugas.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=wifi+hack+pro+apk+free+downloadPDF 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_off0000c22c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC22C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000da3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA3E 16900 bytes
SHA-256: 3f57dda25ba6863a7876660bf385688482bbd9e9c8dc143a7ec6da3344be9ac3
font_02_sfnt_off0001061d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1061D 10620 bytes
SHA-256: 30b95022bf9e7db97072dc77d9262f6f5ff665408a6cd00a5abf9833b7fa1f5a