Malicious PDF — malware analysis report

Static analysis result for SHA-256 3d8a233d999ad9b9…

MALICIOUS

PDF

163.4 KB Created: 2021-10-08 07:02:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 3ad246717766115ec129d72062934764 SHA-1: 3b81969f19d70f538f331d1abb2d16a5e2520ac1 SHA-256: 3d8a233d999ad9b909ac10022828f950b5b24dca5b5e3a094aad1aba063274d4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised WordPress sites, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were extracted, the structure and URL patterns are consistent with a malicious PDF dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9983

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://infrive.ru/uplcv?utm_term=silence+the+court+is+in+session+full+text+pdf PDF link annotation
    • http://vstarmp.cn/upload/files/20210927_085613.pdfIn PDF document text
    • http://puntolinea.org/userfiles/files/jexekowakefekuzegabobux.pdfIn PDF document text
    • https://costarica4d.com/contents/files/47475186590.pdfIn PDF document text
    • http://worksafeorg.com/wp-content/plugins/super-forms/uploads/php/files/g5adrlu775kbo7deahomvra911/16730116304.pdfIn PDF document text
    • http://mgtofubbq.com/uploads/files/ravovu.pdfIn PDF document text
    • http://boxerdapolenta.com/cmsimple/images/file/zekamibanopetojalo.pdfIn PDF document text
    • http://twinmd.ru/userfiles/file/xatoxajivaxin.pdfIn PDF document text
    • http://uticachemical.com/files/upload/files/nikov.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/161466ec177c6e---39594900587.pdfIn PDF document text
    • http://hakasasi.id/userfiles/file/vitunure.pdfIn PDF document text
    • http://magiepourenfants.com/images/mediamanager/file/18713363772.pdfIn PDF document text
    • http://yaqeen-eg.com/userfiles/file/62149026364.pdfIn PDF document text
    • http://onroerendgoedindex.nl/images/uploads/54305143572.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/161421ed591f5c---27554729379.pdfIn PDF document text
    • https://tranhtreo.com/images/ckeditor/files/20322563748.pdfIn PDF document text
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/09e6c417e5c7145767c4afbf49a9a6f5/nijagisixaf.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140a2e36c2f0---jipotawamik.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132619ccc141---wiwojeruvaragi.pdfIn PDF document text
    • https://cjsc.se/ckfinder/userfiles/files/68223776514.pdfIn PDF document text
    • http://lamorenj.com/userfiles/file/95640665663.pdfIn PDF document text
    • https://vvpta-irvine.org/userfiles/file/83266624749.pdfIn PDF document text
    • http://bbfederico2.net/userfiles/file/rifop.pdfIn 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://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_off00021753.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x21753 21284 bytes
SHA-256: e5ab0d71b67f69a3749b06a775f8b868fda957c928eccd1a60ba9ba6b81fea2b
font_01_sfnt_off00024e34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x24E34 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0002664b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x2664B 10832 bytes
SHA-256: 74420073f3fdbdbc1aaab31c83a742340f5effb07cea73ac300036b9dd662275