Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5a48d3b24cb2076…

MALICIOUS

PDF

72.8 KB Created: 2021-09-27 14:02:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: dc0aa832634575d21134158cfc2ba5f6 SHA-1: 65feb45ca2eee82cd85f1aa185d4c1e82a67736b SHA-256: b5a48d3b24cb20761465be1ab0d557e2692e928e27025139c10056e8167b62e8
156 Risk Score

Malware Insights

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

The PDF was flagged by multiple heuristics as containing a link farm, with several URLs pointing to compromised CMS uploads and disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the presence of numerous external links suggests a redirection mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://dentherapia.hu/files/file/76946088924.pdf In PDF document text
    • https://madame-tina.com/ckfinder/userfiles/files/73837638478.pdfIn PDF document text
    • https://sieuthimaycafe.vn/uploads/file/50644017878.pdfIn PDF document text
    • http://domosplast.hu/files/file/93337232665.pdfIn PDF document text
    • https://wemservice.com/ckfinder/userfiles/files/90793034878.pdfIn PDF document text
    • http://madinagirls.com/easydo%20v2.00/files/uploads/12560365165.pdfIn PDF document text
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613f9364a0995---49631630579.pdfIn PDF document text
    • http://german-ex.com/images/blog/file/dokavivesosebibalovi.pdfIn PDF document text
    • http://dienlanhhuubinh.com/upload/files/2609490450.pdfIn PDF document text
    • http://www.heksan.com.pl/file/fejimoxodijadirufo.pdfIn PDF document text
    • http://tid.vn/upload/files/83162126558.pdfIn PDF document text
    • http://eca.or.th/ckfinder/userfiles/files/68979176450.pdfIn PDF document text
    • http://dinskayarealty.ru/media/file/jigugakuzuketexu.pdfIn PDF document text
    • https://namratalakhotia.com/userfiles/files/wogometinojevuvofup.pdfIn PDF document text
    • https://all-stage-meditation.tw/uploads/files/6134c2c5c735f.pdfIn PDF document text
    • http://budget-pl.com/ckfinder/userfiles/files/97310382326.pdfIn PDF document text
    • http://azizavacanze.com/userfiles/files/tabumotumuvixadiwugen.pdfIn PDF document text
    • http://satisfytech.com/ck/upload/files/puxevajozasadu.pdfIn PDF document text
    • https://baruipur.org/ckfinder/userfiles/files/degasu.pdfIn PDF document text
    • http://verzorgingsindex.nl/images/uploads/44285601282.pdfIn PDF document text
    • http://nissanotogovap.vn/uploads/images/files/xeminupiliranugagom.pdfIn PDF document text
    • http://foodzipo.com/uploads/userfiles/files/8283177288.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/3664a6b4d9c88186c4c98f19bc4efd5d/pekuvo.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/b9b8378fe9e774d2dd7b8e08977d075b/89646347928.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=how+to+record+imo+video+call+in+androidPDF 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://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_off0000b5cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5CD 10508 bytes
SHA-256: 6bab2aa6b309162abda6c3999f1f5f08d0158296d2d374dd1b5fc50ec579d10e
font_01_sfnt_off0000cdad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDAD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e5bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5BF 17932 bytes
SHA-256: e2072279fb72398ae495b864216d9e9f8a293c92b0b85c2bd92882aa05c61b04