Malicious PDF — malware analysis report

Static analysis result for SHA-256 6cd1ecfd2a41ee13…

MALICIOUS

PDF

81.9 KB Created: 2021-06-13 11:12:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: f81b3fa54ab352e417a1dc6e9414dc2b SHA-1: bfa8fb822e5035e20f5937252aac37bfac3d6fd4 SHA-256: 6cd1ecfd2a41ee136f297710e695dabe3de07e2132e016d12b7fda20bc46461a
196 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 0.9998

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://synerhu.ru/uplcv?utm_term=choices+stories+you+play PDF link annotation
    • http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/u6ondrhi2d188qka8hjqctqoni/87624863561.pdfIn PDF document text
    • http://bigandtallking.com/userfiles/file/6991816305.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/160a9acb3a7b55---43684067752.pdfIn PDF document text
    • https://bikidi.com/UpFiles/WebEditorFiles/file/99700965587.pdfIn PDF document text
    • http://lushexperiences.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079a0f5f161c---76957023534.pdfIn PDF document text
    • https://cottingham-group.com/cufiles/files/zutijagebawisutedivego.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086c070d9346---gotogu.pdfIn PDF document text
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078ab2359d25---43495661041.pdfIn PDF document text
    • https://cosalesrep.com/wp-content/plugins/super-forms/uploads/php/files/8f3aafa744b1f4c39006df4cb511c817/41829118888.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606f36434ec65---7716515454.pdfIn PDF document text
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/76eb3jh02il23bjr6ub6qvqv53/17451465273.pdfIn PDF document text
    • https://baxsporthorses.nl/userfiles/file/88301964470.pdfIn PDF document text
    • https://nadamasristorante.it/file/juves.pdfIn PDF document text
    • http://narcisse.sk/editor_uploads/files/savovul.pdfIn PDF document text
    • http://traiteur-ribot.fr/userfiles/file/58734888026.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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ebcb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBCB 4924 bytes
SHA-256: 642ad0658ff12551f335b01ea564dc66fcec248fd52b76f827b26b9e50db48ad
font_01_sfnt_off0000fca2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCA2 20464 bytes
SHA-256: 8116e3b94cbf808bfdd56a9cd908ca5c7af70aa6d8081fdf5550d9d1ecec2aed
font_02_sfnt_off00012caa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CAA 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176