Malicious PDF — malware analysis report

Static analysis result for SHA-256 a72eb42f9ecd50c4…

MALICIOUS

PDF

74.9 KB Created: 2021-10-09 16:33:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: a9c983092d42c6d58e891e6b92ad2f24 SHA-1: 231951a49c4b1b5b86810ec301bad5fcd0b474e5 SHA-256: a72eb42f9ecd50c4a455a8c73724a2c79b7e890c19aeb435a5a257e3af01302b
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was identified as malicious by ClamAV and an ML classifier, with heuristics indicating it is a callback phishing lure. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, but the presence of embedded URLs and the 'SE_CALLBACK_LURE' heuristic strongly suggest a phishing attempt. No scripts were extracted, but the PDF structure and embedded URLs are indicative of a malicious document designed to trick users into contacting a fraudulent entity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 6

  • 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.
  • 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://fengshan-zhennangong.org/upload/ckfinder/files/13071012619.pdf In PDF document text
    • http://www.kigimex.com.vn/ckfinder/userfiles/files/13606283680.pdfIn PDF document text
    • https://www.hsbofmn.com/ckfinder/userfiles/files/suzemegezojezaze.pdfIn PDF document text
    • http://www.dilipprabhavalkar.com/images/file/72047678659.pdfIn PDF document text
    • http://tc-muehlacker.de/data/tcmuehlacker/userfiles/file/navimexizuxilibigujuzera.pdfIn PDF document text
    • http://zimmerei-possert.at/tusanexitatiwevema.pdfIn PDF document text
    • http://kashima.cc/userfiles/file/86631337635.pdfIn PDF document text
    • https://shiprapublication.com/uniformkontakt/userfiles/image/files/13823111170.pdfIn PDF document text
    • http://sxhk365.com/uploads/file///kowakogizadojogakazaxife.pdfIn PDF document text
    • https://faktxeber.ru/resimler/files/1365172644.pdfIn PDF document text
    • http://customize.fr/fckeditor/editor/filemanager/connectors/php/img/Editor/file/22563448035.pdfIn PDF document text
    • http://khiconghoixuancong.com/Khicong/admin/userfiles/file/tolajatuxinuxiwirijisoju.pdfIn PDF document text
    • https://comtraining.cl/userfiles/files/kuxisazagotedixamiwo.pdfIn PDF document text
    • https://associazionebriciole.it/public/file/pisulijonijor.pdfIn PDF document text
    • http://labotinnghia.com/img/files/xuvodo.pdfIn PDF document text
    • http://deborahmayerlawoffices.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/35034861158.pdfIn PDF document text
    • http://roosprommenschenckelfoundation.nl/userfiles/file/44632606644.pdfIn PDF document text
    • http://yujinpharma.com/upload/files/53871104789.pdfIn PDF document text
    • http://bukharajohnscreek.com/sites/default/files/file/82778428274.pdfIn PDF document text
    • http://www.papelerialapiceros.es/ckfinder/userfiles/files/manurigedufujuw.pdfIn PDF document text
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/fc618a30ffaaf8265df741978136ff35/70664974876.pdfIn PDF document text
    • https://santeh.md/img/files/xopepefulurepew.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=hour+in+spanishPDF 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_off0000bd48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD48 19788 bytes
SHA-256: c2bf66d87fc7f9e452fe46baf4e4a5b3ebe407be358214e6fae7b5a331fe353c
font_01_sfnt_off0000efeb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFEB 10164 bytes
SHA-256: d80e5e9f34b6b78dd6ed77adc06ae9c4e4d8e9585f3aa837730d52073b547542
font_02_sfnt_off0001067f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1067F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1