Malicious PDF — malware analysis report

Static analysis result for SHA-256 10a66cd2a0d3663c…

MALICIOUS

PDF

84.6 KB Created: 2021-06-20 21:43:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 87da51119237656149ba613d48fda20b SHA-1: 108ace9663ca88204934b46f91f848d5f5c8b3ae SHA-256: 10a66cd2a0d3663cc703c6a77d0cd9b7b5a007e8d35c702c061b529c3e4b3306
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV, indicating malicious content. It contains numerous links, many pointing to compromised CMS upload directories, suggesting a link farm designed to distribute malicious files or redirect users to phishing sites. The document body, though heavily obfuscated, appears to be a lure related to a 'massage business plan example'.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://haenuri.net/ckupload/files/48831967176.pdf In PDF document text
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a22d8b10e70---39645081642.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/16082585da7424---suzupese.pdfIn PDF document text
    • https://lightsourceindiana.com/wp-content/plugins/super-forms/uploads/php/files/483eb45d01f3d699c4e1d3f7b1ac0ce7/83526984006.pdfIn PDF document text
    • http://zkojicin.cz/userfiles/file/lakagimoge.pdfIn PDF document text
    • http://asustainable.com/global/file/29229994172.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/74j3c6atrubpe4oca499iqao5q/kajisijapovilukadirop.pdfIn PDF document text
    • http://446888.top/userfiles/file/62365316168.pdfIn PDF document text
    • http://wksystems.net/HotelEstimator/userfiles/file/lepukijaba.pdfIn PDF document text
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/enr4ivs7hr2igv906k9uqa8020/62144483466.pdfIn PDF document text
    • https://yziact.fr/wp-content/plugins/super-forms/uploads/php/files/c4jn03i1171of223eik4siu4pq/94242632214.pdfIn PDF document text
    • http://collegium-connect.nl/ckupload/files/24415934684.pdfIn PDF document text
    • http://musicupclose.com/clients/f/f7/f7c291dfb329fbc33054893077acf627/File/32769675549.pdfIn PDF document text
    • http://gerd-pollak.de/userfiles/file/nevopawifafiw.pdfIn PDF document text
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/fd0199c601a62d45376bcb519603369a/36803086995.pdfIn PDF document text
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098ce2264673---xoxufoludozazaliwoguxub.pdfIn PDF document text
    • http://aimecostruzioni.it/userfiles/files/24122083178.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/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=massage+business+plan+example+pdfPDF 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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010cd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CD9 5480 bytes
SHA-256: 40b5cc50439e710f84b23f182d7454ad3067a2773c7dd6f0d7020f287627b327
font_01_sfnt_off00011f7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F7B 11204 bytes
SHA-256: 88d8f715abbe5681832d0914b00e1328bf08033d9b2b838ce75f2b855cec9d4f