Malicious PDF — malware analysis report

Static analysis result for SHA-256 82431db41266dc9e…

MALICIOUS

PDF

83.8 KB Created: 2021-09-24 02:37:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 84de10cb1e8d7f8912f642201f9168d7 SHA-1: 1a7be710cbb517bd6035c7e2683d4e9350f7c2f6 SHA-256: 82431db41266dc9ece86817d991231b17a2446f0ac8fecb3cfa6d062dd861eb4
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a high number of external links, many of which are hosted on potentially disposable domains, suggesting a link farm or redirection mechanism. The presence of a 'download button' heuristic further supports the idea that this PDF is designed to trick users into downloading malicious content. ClamAV detection as 'Pdf.Phishing.Trojan' reinforces the malicious classification.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://pro-elec.ru/ckfinder/userfiles/files/sunabapubixitalasuxukaz.pdf In PDF document text
    • https://ibextrail.com/editor-images/7170097177.pdfIn PDF document text
    • https://eko-briketes.lv/userfiles/files/nijojupupukalagaxez.pdfIn PDF document text
    • http://thewellmanteam.com/userfiles/files/60962810030.pdfIn PDF document text
    • https://maurinet.com/userfiles/file/2548479132.pdfIn PDF document text
    • http://orchid-daikanyama.com/userfiles/file/45057607813.pdfIn PDF document text
    • http://belgium-ex.com/images/blog/file/7848940375.pdfIn PDF document text
    • http://ambulatorioveterinarioilprato.eu/userfiles/files/38833990677.pdfIn PDF document text
    • https://cobaltinc.org/userfiles/file/jilokadebagimoxixunal.pdfIn PDF document text
    • https://metrosecuritynepal.com/assets/userfiles/files/xemidu.pdfIn PDF document text
    • https://lmcmanager.com/ckfinder/userfiles/files/4819584328.pdfIn PDF document text
    • http://vinaaquachem.com/uploads/files/gokezomodu.pdfIn PDF document text
    • http://goodmax.ru/i/files/84768226580.pdfIn PDF document text
    • http://ducthai.vn/userfiles/file/kuwezazunerufomoxokiwurit.pdfIn PDF document text
    • https://tekartltd.com/upload/files/wisosabune.pdfIn PDF document text
    • https://www.sesc-am.com.br/Selecao/ckfinder/files/5136723557.pdfIn PDF document text
    • http://dobre-jaja.com/Upload/file/28758843358.pdfIn PDF document text
    • http://brixtontaxi.com/survey/userfiles/files/41855841396.pdfIn PDF document text
    • http://mojahotels.com/ckfinder/userfiles/files/luwafubi.pdfIn PDF document text
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/161302027719ad---nemakinox.pdfIn PDF document text
    • http://faithleader.org/js/ckfinder/userfiles/files/tizevalemolozulabikuw.pdfIn PDF document text
    • http://kp-technik.cz/ckfinder/userfiles/files/61163216151.pdfIn PDF document text
    • https://colakcivi.com/userfiles/file/28893912521.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=change+android+phone+regionPDF 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_off0000e26c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE26C 10388 bytes
SHA-256: e6447cf5f989579b8ce4e8b2a46a630b03f7ed0a3541f0c00f8306dfd9f10296
font_01_sfnt_off0000f996.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF996 18716 bytes
SHA-256: f49b065f32b90dd75d9bf85e4ae5bd509fe104560a18cd86fe05f10d21bde5b1
font_02_sfnt_off000129d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129D6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1