Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ca55cd03d66a206…

MALICIOUS

PDF

87.8 KB Created: 2021-06-12 12:06:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 28498210f3dcd73f5711942a24c60053 SHA-1: 27d7323c478d4f59517b2706e9f0c249d0c91967 SHA-256: 8ca55cd03d66a206977a607de3cf2103ec297e45599946979973c0c13ed8d3c3
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the PDF structure and URL patterns are indicative of a phishing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://infrive.ru/uplcv?utm_term=saisuthe+novels+pdf PDF link annotation
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609e75ea18b8f---82720587575.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/cc9b8b6734611597d656afd450756bf4/68493938788.pdfIn PDF document text
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/89qiodj59bn5p06sm0s7dj5ffh/suwumedomojuxiliz.pdfIn PDF document text
    • https://alshamiltrading.com/alshamilfiles/file/34732676639.pdfIn PDF document text
    • http://2girlstrippin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8c8ec40e5---79244685876.pdfIn PDF document text
    • http://allamericannursing.com/userfiles/file/28424349244.pdfIn PDF document text
    • http://nc2e.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16082cd0d8ca2a---pibusopug.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc192031aff---38822173638.pdfIn PDF document text
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608612b2bc423---feriniwozolexudarijebizob.pdfIn PDF document text
    • https://anjingliar2.com/contents//files/93026064991.pdfIn PDF document text
    • https://usssecuritate.ro/userfiles/file/jitusabi.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160780437dc66f---rezewiwuzagatesipalixola.pdfIn PDF document text
    • https://www.litesourcenc.com/wp-content/plugins/super-forms/uploads/php/files/b518573bbcd31a06d6111ff25d2154f6/kogofidezitim.pdfIn PDF document text
    • http://portalkucharski.pl/app/webroot/media/files/35879606389.pdfIn PDF document text
    • https://davebakeragency.com/wp-content/plugins/super-forms/uploads/php/files/8f9a7ee377753f7ca5dbc86ae19c8e59/35922051576.pdfIn PDF document text
    • http://fedorahosted.org/lohitIn 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off0000ec71.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0xEC71 28516 bytes
SHA-256: 2d7c669afd5eaf2e85969075337522205e5cc31101ba8826b073cacda7c5d92d
font_00_sfnt_off0000dabd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDABD 5196 bytes
SHA-256: 4a21ad3c2e8a244ddbd8cf25f2290c91bf6c64503b7e2c570b1ea6aa64d64fa7
font_02_sfnt_off000123c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123C8 2100 bytes
SHA-256: 3f6c87cf02e27f43515c96d1e60d8fcea07af22be5a9fd8ab174a8d3462e2067
font_03_sfnt_off00012d9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D9F 10572 bytes
SHA-256: ced5a59a5e3c64d80149580081178aa1e3ecdbbff3d3499614cbcc321b122a77