Malicious PDF — malware analysis report

Static analysis result for SHA-256 2c8b28c8391d219a…

MALICIOUS

PDF

83.6 KB Created: 2021-09-11 08:58:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b325b94ffd72872469cade31f0802855 SHA-1: 841681899baee2648ab16edbdb73c72a2860044c SHA-256: 2c8b28c8391d219abcb4f1ae7d1bff9a57b57e21103b659bbf60cfa2813e666d
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ClamAV and an ML classifier, and contains embedded JavaScript. The presence of numerous external URLs, many on disposable hosting, and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic suggest a phishing or scam attempt. The embedded JavaScript likely facilitates the download and execution of a secondary payload, contributing to the overall malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://crewmak.ru/uplcv?utm_term=c%2B%2B+for+everyone+pdf PDF link annotation
    • https://premium-house.uz/images/file/13208746381.pdfIn PDF document text
    • http://gilendor.cz/userfiles/file/26571113337.pdfIn PDF document text
    • https://takipbizde.com/calisma2/files/uploads/51717331326.pdfIn PDF document text
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c39cb7d273---puralosu.pdfIn PDF document text
    • http://vektor28.ru/userfiles/file/22277031156.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/16133e8d7457da---firazerewidorube.pdfIn PDF document text
    • https://manualismedicina.hu/fileok/file/40360378021.pdfIn PDF document text
    • http://refah4ter.info/basefile/hotelrefah4terir/files/xoxikawaxajigitij.pdfIn PDF document text
    • http://splogservice.ru/content/file/31572292471.pdfIn PDF document text
    • http://learningkey.org/userfiles/30393481354.pdfIn PDF document text
    • http://billedbutikken.dk/articlefiles/file/dapapulujevorizafakuwitu.pdfIn PDF document text
    • http://yds-wcv.jp/free_images/files/27227817316.pdfIn PDF document text
    • http://oguzlarotomatiksanziman.com/depo/sayfaresim/file/78430006118.pdfIn PDF document text
    • https://shiokuda2.com/contents/files/1602382617.pdfIn PDF document text
    • http://runbo.net/upfiles/files/16312322629202.pdfIn PDF document text
    • http://www.saveurspoitoucharentes.com/admin/ckfinder/userfiles/files/sudolun.pdfIn PDF document text
    • http://ux02.wadhost.com/js/ckfinder/userfiles/files/48831501417.pdfIn PDF document text
    • https://implant-drill.com/userfiles/file/jalevudures.pdfIn PDF document text
    • http://piqiso.ru/userfiles/file/28126067043.pdfIn PDF document text
    • http://citysoupsbellevue.com/uploads/files/11864551746.pdfIn PDF document text
    • https://peisheng.org/uploads/ckfiles/files/613513ad80b10.pdfIn PDF document text
    • https://www.borzabadi.com/ckfinder/userfiles/files/lujajobiwapaz.pdfIn PDF document text
    • http://shmgec.com/Uploadfiles/files/loloxiwupijotekix.pdfIn PDF document text
    • https://lapalettedesarts.fr/gestion/file/mudoxasinonedotebe.pdfIn PDF document text
    • https://zabulgaria.org/userfiles/file/45808680944.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_off0000e1fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1FD 18592 bytes
SHA-256: cffdb1be422a7819c2faae0dbae52815b39c5d9fb84cd1e904d047c82f6bfcc8
font_01_sfnt_off000111b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111B5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000129cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129CC 10136 bytes
SHA-256: 93889ca55bf493f76cb49782a41d12f8e7d334965300f8a292f738b2dcd94980