Malicious PDF — malware analysis report

Static analysis result for SHA-256 842dcd0f21821f5b…

MALICIOUS

PDF

86.6 KB Created: 2021-06-22 17:07:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: e0dea7e623976c6c5ff35300a26ee95f SHA-1: 4b4391c23c9e7630050f5da6be0c404814f1acd6 SHA-256: 842dcd0f21821f5b83be43f64358710f7e2623f3af9faf14da90cc8d5a0d4256
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. Heuristics indicate it functions as a link farm, with multiple URLs pointing to compromised WordPress upload directories. These links likely serve as lures to phishing or malware distribution sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://sckstone.com/wp-content/plugins/super-forms/uploads/php/files/3a8e50f9f369c08394deb985aad753f8/44562876954.pdf In PDF document text
    • https://godparents4tz.org/home/god/public_html/ckfinder/userfiles/files/30748607124.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb80c36966---60688499176.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ba058123ef8---vovijilerakakezusesopixo.pdfIn PDF document text
    • https://xo-sound.ru/userfiles/file/45080918237.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/16088988015029---zavobir.pdfIn PDF document text
    • http://gilendor.cz/userfiles/file/fowexijabopazire.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160816cf63d843---dosegipupojepadopobugujo.pdfIn PDF document text
    • http://psychologkmalinowska.pl/ckfinder/userfiles/files/46605253976.pdfIn PDF document text
    • https://ipcare.nl/wp-content/plugins/super-forms/uploads/php/files/vakqdb8e3t072vf9gs9p0g9rb9/53693523909.pdfIn PDF document text
    • http://newgatedesign.com/Images_upload/files/tomebeve.pdfIn PDF document text
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ed67aa28d0---58849714211.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/c183b7871d9a5e82105f03fc603b1ec7/tasezebuteloxovazidupoja.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=aptitudes+questions+and+answersPDF link annotation
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fdd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDD3 5128 bytes
SHA-256: 15f41afdc130eb0a3df2e0ce15d5f708410c63ce0891efc2576738bde9f88352
font_01_sfnt_off00010f61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F61 12056 bytes
SHA-256: ffeafed9968fae6ac1153522684c2180c13424b518c0ba9f8e3681c95b56630c
font_02_sfnt_off000138cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x138CD 16144 bytes
SHA-256: 8e5dbdbe927be97d73f8414817a63f4666824eaece580a3f033ced69ff4f47f8