Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc435978dd4f26f7…

MALICIOUS

PDF

85.0 KB Created: 2021-09-10 06:01:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: fc3f44dad630061659913828bffab6f8 SHA-1: d3d0745bb7e194a1ef2cdbe33f392ea18c4aa846 SHA-256: bc435978dd4f26f77b1a281ab6d9b6b734e84f3429abc833d7c26ade1f43f548
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to disposable hosting and appear to be part of a link farm. The document body is heavily obfuscated, preventing analysis of its direct content, but the presence of many external links suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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://krisoc.ru/uplcv?utm_term=top+music+player+for+android+2021 PDF link annotation
    • http://caogenzhiben.com/filespath/files/20210902115249.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16130c338368fb---56733043061.pdfIn PDF document text
    • http://www.oe.com.tw/ezadmin/ckfinder/userfiles/files/gozimazatinosemarebolose.pdfIn PDF document text
    • https://xn--fct8ml6mwue.tw/uploads/files/86042317072.pdfIn PDF document text
    • https://tempegaring.com/contents/files/81036811241.pdfIn PDF document text
    • http://permanentnimakeup-brno.cz/userfiles/files/98386881987.pdfIn PDF document text
    • http://anapharmata.hu/ckfinder/core/connector/php/files/rufulalusamubenemogu.pdfIn PDF document text
    • http://epicridesnepal.com/files/bodujomovagixagudiwibufoj.pdfIn PDF document text
    • http://patanamachine.com/imgUpload/files/73189411016.pdfIn PDF document text
    • http://fteq.ru/files/file/37282195151.pdfIn PDF document text
    • http://hermanosgolbano.com/admin/fckeditor/editor/filemanager/connectors/phpfile/fijetix.pdfIn PDF document text
    • http://medicalproduct.hu/images/files/mafosanekogeledubodezaz.pdfIn PDF document text
    • http://golfproradost.cz/webpagebuilder/ckfinder/userfiles/files/56974908852.pdfIn PDF document text
    • http://wedding-box100.com/uploads/files/202109031651487566.pdfIn PDF document text
    • http://aloisiquadri.it/userfiles/files/917386805.pdfIn PDF document text
    • http://tootingtaxi.com/survey/userfiles/files/vovali.pdfIn PDF document text
    • https://balarampurblock.in/ckfinder/userfiles/files/raseretag.pdfIn PDF document text
    • http://koreabulk.net/userData/board/file/9052949711.pdfIn PDF document text
    • https://100tmt.com/uploadimage/files/20210904055016.pdfIn PDF document text
    • http://syntra.pl/userfiles/file/mewafamunelapome.pdfIn PDF document text
    • http://vietkinggroup.com/uploads/userfiles/file/32130329481.pdfIn PDF document text
    • https://rawoctane.com/uploads/file/26940456626.pdfIn PDF document text
    • http://cachnhietwin.com/luutru/files/64409666449.pdfIn PDF document text
    • http://mgtofubbq.com/uploads/files/83414226046.pdfIn PDF document text
    • http://photopuzzle.net/userData/board/file/viteraki.pdfIn PDF document text
    • https://asiastudy.in/ckfinder/userfiles/files/vetawere.pdfIn PDF document text
    • http://cluboutletmoto.net/campannas/file/tiwuka.pdfIn PDF document text
    • http://ip-golubev.ru/ckfinder/userfiles/files/jodaminutexixewewaxu.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_off0000e766.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE766 11152 bytes
SHA-256: 1bbb0bb3371a86d4973ee0a90ad4d013ac0e69b7a8ec11f2ef5a460062136457
font_01_sfnt_off00010187.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10187 17268 bytes
SHA-256: 10b19c06e71c8b8ba8457debb88138cd6bd55c07ab498177f63d3e458e40147f
font_02_sfnt_off00012e2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E2C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1