Malicious PDF — malware analysis report

Static analysis result for SHA-256 7cae41493af0fbcf…

MALICIOUS

PDF

76.5 KB Created: 2021-09-20 16:50:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: e39f4da296de2ec550801de988b9dc74 SHA-1: 3170cd376238eb4572cf35857893d0b22009c8c7 SHA-256: 7cae41493af0fbcf8cf96c59856e07bfdbecc02673d71250dcf2f633313668da
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a high ML score and ClamAV detection, indicating malicious intent. The presence of numerous external URIs, many pointing to disposable domains and employing UTM parameters, suggests a phishing or malware distribution scheme. The document body, though heavily obfuscated, originates from wkhtmltopdf, a tool often used to generate PDFs from web content, further supporting the idea that the PDF acts as a lure to external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://garglob.ru/uplcv?utm_term=nba+2k14+modded+to+2k16+free+download+for+android PDF link annotation
    • https://armature.ir/cache/fck_files/file/69466006987.pdfIn PDF document text
    • https://ferropula.hr/files/51536725538.pdfIn PDF document text
    • https://hocaukhudothithanhphogiaoluu.com/asset/site/files/netexufifugonobunuxila.pdfIn PDF document text
    • http://cbcom.eu/ressource/site-image/files/burujizorijibajajelamerim.pdfIn PDF document text
    • https://instalacje-elektryczne.net/ckfinder/userfiles/files/vekinelu.pdfIn PDF document text
    • http://ccsilver.kr/files/fckeditor/file/1313442055613d42f28cf1a.pdfIn PDF document text
    • http://mindennapi.hu/upload/file/92029650096.pdfIn PDF document text
    • http://octapus.vn/images/uploads/files/zobojoditi.pdfIn PDF document text
    • http://robalton.es/Albums/images/file///56961830628.pdfIn PDF document text
    • https://sanaspinler.net/calisma2/files/uploads/pafeferumoxuv.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613c8e9e7dea8---25502263280.pdfIn PDF document text
    • https://reniuved.it/file/nodarelowefanujiz.pdfIn PDF document text
    • https://polymadeniyaglar.com/fckeditor/userfiles/file/mojeruruwafudojeruvo.pdfIn PDF document text
    • https://francois-daulte.com/ckfinder/userfiles/files/22253926118.pdfIn PDF document text
    • https://motoralbini.it/files/file/xawofabopewemadaf.pdfIn PDF document text
    • http://ettermanenterprises.com/ckfinder/userfiles/files/433204919.pdfIn PDF document text
    • https://www.borzabadi.com/ckfinder/userfiles/files/98511002147.pdfIn PDF document text
    • http://kammatrans.com/userfiles/files/guxebimut.pdfIn PDF document text
    • https://transturist.ba/ckeditor/ckfinder/files/files/melomometiru.pdfIn PDF document text
    • http://oodow.cn/upload/file/210903013149747545vka8ghdzujgc.pdfIn PDF document text
    • http://lmleadmanagement.com/userfiles/files/toteturoxikovanotitenaz.pdfIn PDF document text
    • http://holidayinntorino.com/userfiles/files/7081897860.pdfIn PDF document text
    • http://mastervin.ru/files/file/14930836126.pdfIn PDF document text
    • http://permanentnimakeup-brno.cz/userfiles/files/82401519547.pdfIn PDF document text
    • 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_off0000c13a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC13A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d951.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD951 11060 bytes
SHA-256: 7fb6a39db972d1885379d6b17495b33bdf4e41c346c0a2a8725d6616da3925ea
font_02_sfnt_off0000f339.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF339 18476 bytes
SHA-256: 043e36bcde757eea66c196b7795a94c80544da49ece58fc16dbad750c09810e3