Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ddb3b4b3d259678…

MALICIOUS

PDF

83.8 KB Created: 2021-09-21 13:13:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 1512dbb0fb6706be48f2c09284bbaf88 SHA-1: bc9594c84cca104163380071ac9b26da6dff3254 SHA-256: 8ddb3b4b3d259678e09078af39d91b11f80713e93af2cda384c688cce315a296
182 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains embedded JavaScript and multiple external URLs, with a high ML classifier score and ClamAV detection indicating malicious intent. The presence of a 'Browser extension / update installation lure' heuristic strongly suggests a social engineering tactic to prompt the user to download and install malicious content. The embedded JavaScript likely facilitates the execution of a second-stage payload from one of the provided URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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 https://garglob.ru/uplcv?utm_term=how+to+see+bluetooth+received+files+in+windows+10 PDF link annotation
    • https://architektor.ru/uploads/file/19065465388.pdfIn PDF document text
    • http://zjqzzx.com/uploadfile/file/2021090312332473499.pdfIn PDF document text
    • http://aviapartner.biz/js/ckfinder/userfiles/files/46178017937.pdfIn PDF document text
    • http://www.veslovani-vsb.cz/soubory/file/jumaxosafudafekatosomefe.pdfIn PDF document text
    • https://www.indoorclub-informa.com/boletines/img/file/kopigoxexe.pdfIn PDF document text
    • http://kopdesign.nl/userfiles/file/gumusijus.pdfIn PDF document text
    • http://vet-arrighicolangelicristilli.eu/userfiles/files/sapifamedopoduvozafaxejos.pdfIn PDF document text
    • https://moraure.net/js/ckfinder/userfiles/files/44744596946.pdfIn PDF document text
    • https://homeuu.biz/upload/ckeditor/pages/files/41085621084.pdfIn PDF document text
    • http://aksaxena.com/bpms/includes/fckeditor_uploads/userfiles/file/titasag.pdfIn PDF document text
    • https://daulte.ch/ckfinder/userfiles/files/xerisuforo.pdfIn PDF document text
    • http://metabolit-plus.ru/files/file/83068041802.pdfIn PDF document text
    • http://hurtmar.pl/Upload/file/zigepovuzetoregipagime.pdfIn PDF document text
    • http://siripanyalamphun.com/user_img/files/tufuxumos.pdfIn PDF document text
    • http://nj-rshb.com/v15/Upload/file/20219317458208.pdfIn PDF document text
    • http://shqinze.net/admin/upimg/file///19553448738.pdfIn PDF document text
    • http://soupworld.de/upload/file/rokaxejuwirirufovuga.pdfIn PDF document text
    • http://evrokomplekt.ru/userfiles/file/dixamoxo.pdfIn PDF document text
    • https://www.jdconstinc.com/ckfinder/userfiles/files/wujelanudeguregaraxize.pdfIn PDF document text
    • https://beaszemin.com/files/padowaniwetomu.pdfIn PDF document text
    • http://stevis.cz/files/file/8517571882.pdfIn PDF document text
    • https://eyetracking.pl/userfiles/file/kesefofuvivu.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_off0000dd3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD3E 19452 bytes
SHA-256: b2adf36df3b1b6e90a1497c0b28c5f056ef32ebcf68ed90051a8eb0b1f396098
font_01_sfnt_off00010f98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F98 10968 bytes
SHA-256: 94cfbcfe0523df59c547b4283b1da04915f55e2f0186c2635c6483f3fe67b737
font_02_sfnt_off0001290f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1290F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1