Malicious PDF — malware analysis report

Static analysis result for SHA-256 f903e8cba0170e4b…

MALICIOUS

PDF

81.9 KB Created: 2021-09-21 13:07:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 08cc80b70be4f0c98cc8be4e479adcaf SHA-1: 835de85e264168e06dfb59be7ec6d61ba7243349 SHA-256: f903e8cba0170e4b2c9ee2d4b67c3825b14b049e64dda950211804e9cf7dd577
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it's a link farm and a callback phishing lure. The document body is heavily obfuscated, but the presence of external URIs and the callback lure heuristic strongly suggest a phishing attempt designed to trick users into calling a fraudulent number. No scripts were extracted, but the PDF structure and embedded URIs are indicative of a malicious document, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16149a8f58909d---dipoloxavivexugifojipa.pdf In PDF document text
    • http://terremeraude.com/userfiles/file/77333970293.pdfIn PDF document text
    • http://thaifilmind.com/upload/files/93735801197.pdfIn PDF document text
    • https://foodphotoshop.com/userfiles/files/51787744266.pdfIn PDF document text
    • https://carsen.sk/editor_uploads/system/files/nakewokixuz.pdfIn PDF document text
    • https://dragonexpressml.com/userfiles/files/sapat.pdfIn PDF document text
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/ee64f1b0d99e8e9c17cf967e49cca1ae/8064007158.pdfIn PDF document text
    • http://mondoacquapiscine.com/userfiles/files/23981553405.pdfIn PDF document text
    • http://portaldeaquidauana.com.br/ckfinder/userfiles/files/mugujijamakezuxabebom.pdfIn PDF document text
    • http://channelletterguide.com/ckfinder/userfiles/files/4659756946.pdfIn PDF document text
    • http://bbpcosmetics.com/admin/upFiles/2021-9/file/65898103213.pdfIn PDF document text
    • http://www.iuoelocal870.com/kaizen/ckfinder/userfiles/files/zexeke.pdfIn PDF document text
    • http://www.amedna.com/userfiles/files/82586971841.pdfIn PDF document text
    • http://oaklandscreche.ie/userfiles/files/nobikef.pdfIn PDF document text
    • http://resortcrimea.com/ckfinder/userfiles/files/bemiwiganuleroropapav.pdfIn PDF document text
    • https://alamansyria.com/userfiles/file/xulisuxezugetisa.pdfIn PDF document text
    • http://bergepkolcsonzo.hu/userfiles/file/61818477840.pdfIn PDF document text
    • http://playbabydoll.com/userfiles/file/4917816825.pdfIn PDF document text
    • https://ehotelgateway.com/bot/ckfinder/uf/files/43570840346.pdfIn PDF document text
    • https://egf.tw/test2/images/file/vuduvosadajid.pdfIn PDF document text
    • http://premo.at/userfiles/file/28978837553.pdfIn PDF document text
    • http://szintai.hu/ckfinder/userfiles/files/duvavazepabijumake.pdfIn PDF document text
    • http://hondatayho.top/img-ngocbao/files/40508937962.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=via+horoscope+movie+appPDF 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_off0000da0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA0D 18552 bytes
SHA-256: 62e6d31009266c4eb90b876721ac8fa8f932d6543d05bff816b14c8d64969853
font_01_sfnt_off00010a8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A8B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000122a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122A2 10428 bytes
SHA-256: 149f6caac579f218fadcbca742e939b24f2e54ea6178ad8545a72547c51ec5a1