Malicious PDF — malware analysis report

Static analysis result for SHA-256 b55967bdc3db700d…

MALICIOUS

PDF

71.9 KB Created: 2021-09-22 17:50:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 4c0491975dab63b47403f07e8f5891c4 SHA-1: bbdc17ce5a86c870b59bf9886f74db5c6961943e SHA-256: b55967bdc3db700d49f219c3bf9a65bae6459e9e193debfd20e13e9f719edf6c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous external links, many of which point to other PDF files hosted on potentially disposable domains, suggesting a link farm or redirection mechanism. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a tactic to obscure the true destination or host malicious content. While no scripts were explicitly extracted, the nature of the links and the PDF structure suggest it's designed to lead users to malicious content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://pottoka.info/files/galeria/files/95572635246.pdf In PDF document text
    • https://aecvfcom.nrgence.com/upload/userfiles/files/pifezafimagujij.pdfIn PDF document text
    • https://corianderedmonton.com/ckfinder/userfiles/files/xadevifuko.pdfIn PDF document text
    • http://mikailang.com/userfiles/file/20210904223304_1263250668.pdfIn PDF document text
    • https://ctyhoanongangiang.com/userfiles/file/milapuriruziwajigogutege.pdfIn PDF document text
    • http://ambartakip.net/belgeler/file/51483609047.pdfIn PDF document text
    • http://firegallery.ru/img/upload/4000958501.pdfIn PDF document text
    • http://albertf.madteam.net/ckfinder/userfiles/files/vabasovepikamu.pdfIn PDF document text
    • https://jooli.ru/ckfinder/userfiles/files/33465018576.pdfIn PDF document text
    • http://mtreurope.com/ckfinder/userfiles/files/zirisaxi.pdfIn PDF document text
    • http://bachova-terapia.sk/images/file/sunikubazofivotumunurujex.pdfIn PDF document text
    • https://btegypt.com/file/93092297468.pdfIn PDF document text
    • https://www.abandassociates.com/ckfinder/userfiles/files/79275332643.pdfIn PDF document text
    • http://bluecreator.biz/ckfinder/userfiles/files/72079805758.pdfIn PDF document text
    • https://baruipur.org/ckfinder/userfiles/files/25985764314.pdfIn PDF document text
    • http://didongsinhvien.com/upload/files/vejojevujenobasu.pdfIn PDF document text
    • http://dirpub.org/editor/ckfinder/userfiles/files/kotubetusozasazize.pdfIn PDF document text
    • https://taipeitccia.org/CKEdit/upload/files/gisafubunipidiruda.pdfIn PDF document text
    • http://luisacortesearchitetto.it/userfiles/files/foruzedebadiperex.pdfIn PDF document text
    • https://honkakuji.jp/honkakuji/images/ckfinder/files/11839583776.pdfIn PDF document text
    • https://gimenezricarte-deltabogados.com/ckfinder/userfiles/files/pifonawazujuwolali.pdfIn PDF document text
    • http://tsrmmessina.it/userfiles/files/34038756772.pdfIn PDF document text
    • https://dijitalsanat.link/upload/files/72309551004.pdfIn PDF document text
    • http://jsdarvin.com/files/vulapa.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/gajevukuraxobomujopusa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=android+reduce+image+sizePDF 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_off0000b7f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB7F3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d005.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD005 16420 bytes
SHA-256: 77af5f5e99b861fd4bc728236e602cb547e25894bf73eb0bafb60887c6356598
font_02_sfnt_off0000f9a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9A1 10712 bytes
SHA-256: ace6367f602d3b96263e086fcb99978f9474b576cc53bc061d67f1ba4bd652e3