Malicious PDF — malware analysis report

Static analysis result for SHA-256 427a0ab34d037759…

MALICIOUS

PDF

81.8 KB Created: 2021-09-08 23:35:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 1b66c173bd6feb9989202689419635ad SHA-1: 612464f3c98b37f46a2224e845d22236de380fb0 SHA-256: 427a0ab34d037759479eb9efadeed1642b34b1cdf8bf941460de1ec41ad90535
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

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 embedded URLs and the PDF structure suggest an attempt to redirect users to potentially malicious websites, likely for phishing or malware distribution. No scripts were extracted, but the PDF structure itself is indicative of a malicious lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://medvor.ru/uplcv?utm_term=besplatno+skidanje+aplikacija+za+android PDF link annotation
    • http://ttccid.com/userfiles/files/repegexufik.pdfIn PDF document text
    • http://tongchangkj.com/uploadfile/file///2021090608574055.pdfIn PDF document text
    • http://ngocphuocjsc.com/public/default/ckeditor/files/48647827073.pdfIn PDF document text
    • http://njbeihang.com/uploadfile/file///2021090505294168.pdfIn PDF document text
    • http://hyosangjo.com/userfiles/file/20210904233400.pdfIn PDF document text
    • https://xn--49st2et51duvk.com/upload/files/63694138343.pdfIn PDF document text
    • http://healingtown.org/userData/board/file/noberivuzoramisovi.pdfIn PDF document text
    • http://henghuitong.com/jingkelun/userfiles/files/20210907233127.pdfIn PDF document text
    • http://gat-asset.com/CKEdit/upload/files/53459812009.pdfIn PDF document text
    • https://olterus.net/contents/files/72419900645.pdfIn PDF document text
    • http://peoplefoster.com/pliki/50599116525.pdfIn PDF document text
    • http://rts-3.ru/upload/files/48565346188.pdfIn PDF document text
    • http://zensushialiso.com/uploads/files/webebovesojovozoruwaves.pdfIn PDF document text
    • http://dralituncer.net/userfiles/file/muramebozewulurox.pdfIn PDF document text
    • http://japan-railpass.info/images/blog/file/24916533239.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130dd8ce45e8---30659853070.pdfIn PDF document text
    • https://soechi.id/userfiles/file/66829463911.pdfIn PDF document text
    • http://caerulumpharma.com/upload/files/39044678866.pdfIn PDF document text
    • https://codecs.ro/images/file/70854954597.pdfIn PDF document text
    • https://tommytest.dish1314.com/data/html_editor/files/dijaxi.pdfIn PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/16134f0c9e350e---21154412488.pdfIn PDF document text
    • http://osheamaloneynylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/4544145932.pdfIn PDF document text
    • https://ldcpc.com/ckfinder/userfiles/files/nonitu.pdfIn PDF document text
    • https://china-glass-mosaic.vegner.com/userfiles/files/20210903_124436.pdfIn PDF document text
    • http://cainghienbinhduong.com/uploads/userfiles/file/nowuzopudi.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_off0000dbe4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBE4 10844 bytes
SHA-256: befa7faac8a6fd2ab9767b50848d37a50290667d29f6474e12d43ce764ca4b2e
font_01_sfnt_off0000f51c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF51C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010d2e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D2E 17208 bytes
SHA-256: 3495d02e61cffd73dc8d6a3e84dd97d3dd72a38047ba6dbc9d5b7091792f1381