Malicious PDF — malware analysis report

Static analysis result for SHA-256 f79c843344206539…

MALICIOUS

PDF

80.8 KB Created: 2021-09-10 01:57:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 2c4d870418cf517bea783bb939c28eb7 SHA-1: 7405e7a8b69d8b6acb3be4d5d4347f4ec929cd5b SHA-256: f79c843344206539f90925e70800202d4be0b3b2566d04cf5249a2f3986119ff
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by multiple heuristics, including ClamAV and an ML classifier, indicating malicious intent. The presence of numerous links to potentially disposable hosting sites, coupled with the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic, suggests a phishing or malware distribution scheme. Although no scripts were directly extracted, the PDF structure and embedded URIs point towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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://signatureshreyas.in/userfiles/file/43959637615.pdf In PDF document text
    • http://twapp.freshkon.com/upload/files/45740134012.pdfIn PDF document text
    • http://www.videobezopasnost.ru/ckfinder/userfiles/files/73996391201.pdfIn PDF document text
    • https://zagi.hr/files/42387237837.pdfIn PDF document text
    • http://zapatosperezcabrera.com/ckfinder/userfiles/files/voxobu.pdfIn PDF document text
    • http://1hozain.ru/files/userfiles/files/57526419280.pdfIn PDF document text
    • http://sakem.org/userfiles/files/51832121258.pdfIn PDF document text
    • https://heatingboiler.ca/fck_upload/file/81998507218.pdfIn PDF document text
    • http://aumnat2car.com/ckfinder/core/connector/php/upload/files/jewuzalikamuxaj.pdfIn PDF document text
    • http://abwninemile.com/uploads/files/30126095654.pdfIn PDF document text
    • http://idcla.net/upload/files/muriw.pdfIn PDF document text
    • http://miwon.com.vn/app/webroot/uploads/files/wubet.pdfIn PDF document text
    • http://4rrecycle.com/files/file/89070686076.pdfIn PDF document text
    • http://auto-rad.pl/userfiles/file/duvibuwumabifosixubuz.pdfIn PDF document text
    • https://callhfelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138fa86a1bed---19388318733.pdfIn PDF document text
    • http://leebyunghun.org/new/upload/board/files/30162539905.pdfIn PDF document text
    • http://modero.vn/upload/files/86868679481.pdfIn PDF document text
    • http://caramelitos.sk/files/67744256128.pdfIn PDF document text
    • http://www.onlinenieuwsbriefversturen.nl/gebruikers/afbeeldingen/suravita.pdfIn PDF document text
    • http://jinsonmetal.com/Upload/file/rosadiwos.pdfIn PDF document text
    • http://hanmih.com/userfiles/file/20210908041507.pdfIn PDF document text
    • http://sbcnepal.com/images/file/sexitepa.pdfIn PDF document text
    • http://backkwang.com/userData/board/file/kegavozumetunozosok.pdfIn PDF document text
    • https://cairparavel.ro/app/webroot/files/userfiles/files/vivugilonom.pdfIn PDF document text
    • http://phulieumaymacbaoco.com/hinhanh_fckeditor/file/sodik.pdfIn PDF document text
    • http://ebara.com.hk/ckfinder/Zenith/userfiles/files/xakepiraped.pdfIn PDF document text
    • https://coopinproject.eu/ckfinder/userfiles/files/kilop.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161345f4a09414---fogilenodumutazi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=hitman+sniper+apk+download+freePDF 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_off0000d803.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD803 10828 bytes
SHA-256: c2091dde8e0b825768d4a2f09d25f59c0239a167d12667277c16044d5838dd2e
font_01_sfnt_off0000f0f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0F6 16940 bytes
SHA-256: 373d7ff409d0c0097dad9cbaa5e509d6e8d18633b2099e8b706e3850d1ab880f
font_02_sfnt_off00011ccb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CCB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1