Malicious PDF — malware analysis report

Static analysis result for SHA-256 924c50c94c109916…

MALICIOUS

PDF

80.3 KB Created: 2021-09-20 00:44:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: e64246dbe2abf8efb87c743bcfdd4dff SHA-1: 900b02167de291e420d8b77f4ee6e884d4a8b99b SHA-256: 924c50c94c10991630ae3b326eeb9846a70a987385ea5aeae2c900a0050064ca
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as a phishing trojan and ML classifier indicated high maliciousness. Heuristics indicate it functions as a link farm, with many URLs pointing to potentially compromised WordPress sites or disposable hosting, likely serving as a lure for users to download further malicious content. The presence of embedded URLs and the 'Fake invoice / payment lure' heuristic strongly suggest a phishing or social engineering attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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://catamma.ru/uplcv?utm_term=english+sentence+structure+pdf PDF link annotation
    • https://livre-art.com/ckfinder/userfiles/files/nirikusijururuj.pdfIn PDF document text
    • http://decamiones.com/userfiles/file/97635907.pdfIn PDF document text
    • http://drumlockingclamp.com/FCK_Editor_Images/files/ralujizeni.pdfIn PDF document text
    • http://kbautotech.com/board/datafiles/imagefile/mibagofelejerisafulo.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135ef5c64e75---kifibesakigitide.pdfIn PDF document text
    • http://elmiraclassiccountry.com/wp-content/plugins/super-forms/uploads/php/files/c79be3210089bf8eceee6d42de8f7287/bizudanigolorabola.pdfIn PDF document text
    • http://gsemilia.it/userfiles/files/9441696810.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613f05ea4cbd8---mekibogigofapemozebugu.pdfIn PDF document text
    • https://taucaotoccatba.vn/images/news/files/60006685571.pdfIn PDF document text
    • http://synerfreight.com/syner_upload/images/files/17279630498.pdfIn PDF document text
    • http://kayamedbursa.com/userfiles/file/22586458107.pdfIn PDF document text
    • https://duvarkagidierzincan.com/userfiles/file/48730737322.pdfIn PDF document text
    • http://lube-stc.com/ckfinder/userfiles/files/59278896902.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161450d4b67a67---29130107654.pdfIn PDF document text
    • http://se-ty.com/uploads/userfiles/file/sotupunifegopadot.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/weporuruvofarukaka.pdfIn PDF document text
    • http://tc-antey.ru/uploads/files/22535083084.pdfIn PDF document text
    • http://utcsp2.rustyramone.com/uploads/files/nagevutozavuginesaxigilu.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_off0000d6fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6FC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF13 10700 bytes
SHA-256: 7a03e9927055c72043e99bd6012814d858368d2daeca2396d255f9bc6fe5eb9a
font_02_sfnt_off00010749.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10749 17264 bytes
SHA-256: cd41b700023c52584202008ba07f55a77ce246214a6c6ec8419b4fa157df3422