Malicious PDF — malware analysis report

Static analysis result for SHA-256 23b54c1f1c82cf2c…

MALICIOUS

PDF

80.9 KB Created: 2021-06-14 20:20:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-23
MD5: c4fa1154d6f7ce20ee54136bbbdb7992 SHA-1: fef008e6b24a088394dcadf81d30d7bf4e40cfc5 SHA-256: 23b54c1f1c82cf2c3f27cb3b045370e2f11221fd0076aa2019b9a91d058bcae5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains numerous embedded links, many pointing to disposable hosting or compromised WordPress sites, suggesting a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or serving a secondary payload. No scripts were extracted, but the link farm and overall structure are indicative of a lure to external malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • 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.
  • 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=japanese+numbers+worksheet+pdf PDF link annotation
    • http://abwingscolley.com/uploads/files/69513398827.pdfIn PDF document text
    • http://reszke.pl/fckeditor/editor/filemanager/connectors/php/file/37456729655.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607005dfbd570---dopatizewuti.pdfIn PDF document text
    • https://alphaveneers.co.uk/wp-content/plugins/super-forms/uploads/php/files/1b8ff90415bd38f6711467a2ee6e71b5/67423078208.pdfIn PDF document text
    • https://masterpieces-mallorca.com/wp-content/plugins/super-forms/uploads/php/files/cd90ce2b18cf02207b3025a5627a830d/nugadeva.pdfIn PDF document text
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b05cfde92f7---waluvunebirer.pdfIn PDF document text
    • http://deforma.it/userfiles/files/49036699517.pdfIn PDF document text
    • http://banghetretruc.com/media/ftp/file/kifexuni.pdfIn PDF document text
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608c4c364123b---wimadilegetugetezap.pdfIn PDF document text
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/27f408043e9ccd7707d350f7b922086e/48190587995.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078f253795ab---77892955097.pdfIn PDF document text
    • https://suemsas.com/wp-content/plugins/super-forms/uploads/php/files/50vr6v7705juuq524grl8cvhu6/bigujuzefozinen.pdfIn PDF document text
    • http://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b68f4ca590---rokifefipelinufiv.pdfIn PDF document text
    • https://zweiund40.com/wp-content/plugins/super-forms/uploads/php/files/uvc6749qnkve15vr2l8ecp8u7o/majobolurugala.pdfIn PDF document text
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/7eaadf0e5abbfa8bc0e3dc0463e9801f/xolunigolugiwujo.pdfIn PDF document text
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/16083663ba2d34---fofoba.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ee93.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE93 4276 bytes
SHA-256: 576a0ce879ae01a3cf658d269e0248edd5bbc0e6a0105182f2e58948435701a5
font_01_sfnt_off0000fdc6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDC6 5532 bytes
SHA-256: 4be09a62290807806950b0c5ea0967b429a0b968bd3e85c1c916ed9a9d5c7ab5
font_02_sfnt_off00011076.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11076 11212 bytes
SHA-256: 4ad4c007de4e93fc7324e0e56bdc840eee15be9471c69fb33d3965dbb8a0b67c