Malicious PDF — malware analysis report

Static analysis result for SHA-256 3bf51e8ed14ed85e…

MALICIOUS

PDF

121.6 KB Created: 2021-06-14 02:30:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: 101e2b3c69b293d5a0fdd36afffa205b SHA-1: 9e3074923e9fb975863e92923050d743859907e4 SHA-256: 3bf51e8ed14ed85e9184dafe61e87e6ff573b28689180707bfc43feef4a3f4d5
156 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. 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 0.9997

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=elementary+linear+algebra+with+applications PDF link annotation
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b3e21fd5ef4---54440753863.pdfIn PDF document text
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c42e173d1e0---14159602565.pdfIn PDF document text
    • https://amiablediamonds.com/wp-content/plugins/super-forms/uploads/php/files/ccc2654cc2109ae544ee484c3b87b935/53694655741.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160793b05c5093---gokinujawavunivunag.pdfIn PDF document text
    • http://msiutilities.biz/documents/67506523634.pdfIn PDF document text
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e51164061c---37179133179.pdfIn PDF document text
    • https://www.kbstephens.com/wp-content/plugins/super-forms/uploads/php/files/39a57ff25bc59a569340f51a5dffbb72/58222517202.pdfIn PDF document text
    • https://iphonerepairservice.nl/app/webroot/files/userfiles/files/papixufizibogukufewi.pdfIn PDF document text
    • http://aliceinformaticasrl.com/user/pages/41832533687.pdfIn PDF document text
    • https://best-turbos.com/wp-content/plugins/super-forms/uploads/php/files/6b949eb0a5e0d8669d576bd78f69399d/30086156692.pdfIn PDF document text
    • http://spoanalyze.com/wp-content/plugins/super-forms/uploads/php/files/3109f5cca7477313919be731413e9fff/68073190838.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082f65d6d0c1---diwive.pdfIn PDF document text
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16095fc70c50a5---99646896755.pdfIn PDF document text
    • http://sumnerclassof1976.com/clients/4/49/49b54eafcc86ae0c30eb104ab8b91c7c/File/nuxatadakibev.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001742c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1742C 5428 bytes
SHA-256: 8675352c71fedff4f6b5249d764b54a7850c6a8b7124f7d119aee8a34bb7322b
font_01_sfnt_off0001867d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1867D 13204 bytes
SHA-256: 46c8aee5ee772ece340fc2186dbe3470fe59c2ea6f0d7be3aacdf42292ab71da
font_02_sfnt_off0001b281.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B281 16916 bytes
SHA-256: de7695fe504896b88296fcfa7624c3e419ae00222a5a1eb469385aaa2feadb72
font_03_sfnt_off0001cab7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1CAB7 4324 bytes
SHA-256: 9f355172d696dda274cac500966718f112ce76951f19577ac4888987ea6471b2