Malicious PDF — malware analysis report

Static analysis result for SHA-256 d98e9f9afabdea00…

MALICIOUS

PDF

90.5 KB Created: 2021-06-13 19:09:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: 2228b53b7ffdefe8b0d96ab6fe562d9e SHA-1: c5aadef11cae877005ba6b977f5c90d203f2c0e3 SHA-256: d98e9f9afabdea0094d30d81f80dc433c36668b0670db64ecbc7feda33c62aec
164 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses an invoice-themed lure. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://cructi.ru/uplcv?utm_term=operation+of+function+worksheet PDF link annotation
    • https://chpcentre.com/files/file/20472529233.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7b2b0cf412---79209654213.pdfIn PDF document text
    • http://colorfusion.us/admin/images/file/52834747419.pdfIn PDF document text
    • http://bangtaisay.com/uploads/userfiles/file/11607406610.pdfIn PDF document text
    • https://refour.eu/wp-content/plugins/super-forms/uploads/php/files/55ccec8216a8d95d6fc0f87cc45591c8/47205797064.pdfIn PDF document text
    • http://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c015e4c68ea---divomezajo.pdfIn PDF document text
    • https://viajespereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608954b604529---23725920756.pdfIn PDF document text
    • http://worksafeorg.com/wp-content/plugins/super-forms/uploads/php/files/6oci29eadstf162kmf53o5uoo0/18577607000.pdfIn PDF document text
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/ada21713e0328019a663bf73e5c025aa/pasuvakadakunidav.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/vkdmoc7uhujipggr27l5tb2947/4141888228.pdfIn PDF document text
    • https://funkydrop.shop/wp-content/plugins/super-forms/uploads/php/files/6c24d8b1a4dc5612112e1f7d1b9f52ab/nanezezokabesirijof.pdfIn PDF document text
    • http://teenaramainc.org/clients/875997/File/56682145893.pdfIn PDF document text
    • https://baxsporthorses.com/userfiles/file/xizaveregedabavab.pdfIn PDF document text
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608bb32926e7a---gulupo.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a35f68280c4---7525310770.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00012477.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12477 5252 bytes
SHA-256: d2eedbdbbad268ab122a693ba3294d054b9065568dda2c17da54ba91778f5379
font_01_sfnt_off00013665.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13665 11416 bytes
SHA-256: 3ee26c8f1e435632874ea8e448f3d701a867fb3bf7fabc77a1f3834bc4ce4936