Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd61f7920cc4c840…

MALICIOUS

PDF

74.8 KB Created: 2021-09-12 15:36:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 4b1a0d30b044fce352242c00ec1e1d69 SHA-1: 69a66c9679548d93e9f66cdcb6050e446d03a385 SHA-256: cd61f7920cc4c8407c88aad82fc7c8cd13472db2d0777a23d477eb103832d3fe
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded links, many pointing to potentially malicious domains, suggesting a phishing or malware distribution attempt. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic indicates a deliberate effort to create a link farm on disposable hosting, further supporting this. While no scripts were explicitly extracted, the nature of the embedded links and the ML classifier's high confidence score point towards malicious intent, likely involving the exploitation of PDF vulnerabilities or social engineering to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • 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.
  • 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://ekbdrive.ru/ckfinder/userfiles/files/senuneboxosizorefina.pdf In PDF document text
    • https://esofagopisa.it/userfiles/file/86134722202.pdfIn PDF document text
    • http://unternehmensberatung-hegenbarth.de/userfiles/file/56774297227.pdfIn PDF document text
    • http://ganteltechnology.com/system/userfiles/file/gomikanuzeparewanudefodo.pdfIn PDF document text
    • http://leylatoprak.com/userfiles/file/54955011098.pdfIn PDF document text
    • http://rideabikenews.com/user_img/files/43956122408.pdfIn PDF document text
    • http://longruiglass.com/ckfinder/userfiles/files/20210911_152226.pdfIn PDF document text
    • http://xn--22cjbbm2eyae3ehabdb4kqdtae3dxnnc1fhf.com/user_img/files/kejosob.pdfIn PDF document text
    • http://neonatal-surgery.ru/userfiles/files/66749572174.pdfIn PDF document text
    • http://avandcie-energy.fr/ckfinder/userfiles/files/jamogiwuzezaretiga.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c0d8014a9c---97051463303.pdfIn PDF document text
    • https://echipamente-scule.ro/userfiles/file/nifibe.pdfIn PDF document text
    • http://investinwielkopolska.pl/application/lib/ckfinder/userfiles/files/87665156804.pdfIn PDF document text
    • https://stepweystudy.com/ckfinder/userfiles/files/31976242197.pdfIn PDF document text
    • https://watertorens.nl/userfiles/file/85014916467.pdfIn PDF document text
    • http://sartor.ru/upload/files/85553881813.pdfIn PDF document text
    • https://ppuhperspektywa.pl/files/edytor/file/60559764264.pdfIn PDF document text
    • https://vaynhanh365.net/contents/files/genunovidav.pdfIn PDF document text
    • http://expnavi.com/sites/all/sites/default/files/file/vusumurofifonewa.pdfIn PDF document text
    • http://anneadamslaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/niziteminakopotupemurub.pdfIn PDF document text
    • http://ricarda-allegra.de/userfiles/file/vofanuwatodojisez.pdfIn PDF document text
    • https://pianotuningdarwin.com/userfiles/files/15834241677.pdfIn PDF document text
    • http://optimaglobal.net/ckupload/files/bexos.pdfIn PDF document text
    • http://bbpcosmetics.com/admin/upFiles/2021-9/file/65898103213.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=pokemon+light+platinum+3dsPDF 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_off0000b77e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB77E 11104 bytes
SHA-256: 72ee9da96aab90704b6d934852059bcb8a7baf3bd8df76dc94932acc363d9234
font_01_sfnt_off0000d101.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD101 19740 bytes
SHA-256: 52b0d6a57a7466bb21bf61b9e16c0b5ddffe3ae4f4cf0f04f4cf50bd32a8edf3
font_02_sfnt_off00010592.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10592 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1