Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a91f36fce740b33…

MALICIOUS

PDF

97.1 KB Created: 2021-09-07 11:16:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: b807818c11fc027827c1ed46c65ea46e SHA-1: d04c07b972fba427888aed743bcb315b854607df SHA-256: 3a91f36fce740b335cee29cbb387d2a28174b0fe5173f15c55fe538e52c19da0
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

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 and contains embedded JavaScript. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://nomylo.ru/uplcv?utm_term=le+bouddhisme+du+bouddha+pdf PDF link annotation
    • http://chemonova.com/FCKeditor/file/tebegutilo.pdfIn PDF document text
    • http://geosond.pl/userfiles/file/mozoxisototesi.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5dc08346f1---86212817281.pdfIn PDF document text
    • https://stephan-kratt.de/data/reiterhof/userfiles/file/14243220358.pdfIn PDF document text
    • http://khaskhaan.mn/uploads/userfiles/files/89719152575.pdfIn PDF document text
    • http://regalmotors-jp.com/js/upload/files/66286672421.pdfIn PDF document text
    • http://seibyou-koujien.com/files/files/sejibaverigozozutufujib.pdfIn PDF document text
    • http://luluscafeonline.com/uploads/files/18266305282.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf5e784df1---jukonugogifarunuk.pdfIn PDF document text
    • https://garyjetcenter.com/wp-content/plugins/super-forms/uploads/php/files/092cc86787c8299cacc0ec1b3b103049/89582728884.pdfIn PDF document text
    • http://xenangheli.vn/public/files/xuwanifisoxibenoraxa.pdfIn PDF document text
    • http://ajtoablakcentrum.com/_user/file/75482450589.pdfIn PDF document text
    • https://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/i0pmvocan949monqbrqemc2fcp/gepatonabovube.pdfIn PDF document text
    • https://interesttour.com/wp-content/plugins/super-forms/uploads/php/files/dfae3c030ace02c51182b665c2d79b0f/2899401839.pdfIn PDF document text
    • http://studionegro.net/userfiles/files/81439219661.pdfIn PDF document text
    • http://anapharmata.hu/ckfinder/core/connector/php/files/pefimutivefukexulara.pdfIn PDF document text
    • https://sdudyogtechnologies.in/ckfinder/userfiles/files/49263708137.pdfIn PDF document text
    • https://sportli.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160bc2b9d1665d---foberigifagewu.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b0626a71a2---nuforugovixivukid.pdfIn PDF document text
    • http://cathyknightwaite.com/ckfinder/userfiles/files/41561317824.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf8502c8e0---80330981430.pdfIn PDF document text
    • https://www.couleurs-et-jardin.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160819a308dcac---mupisatonojube.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f9ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9AC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000111c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111C3 10612 bytes
SHA-256: 5fa5de34460cf37e09aea14f18bfa8d1cbd80867d1ed9d45a031223d555fcfc4
font_02_sfnt_off000129b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129B8 5564 bytes
SHA-256: 83cca712feb8083bf5e85677b77b53f4d97dc96aa96a9ee28522c356c4343501
font_03_sfnt_off00013d5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D5E 22708 bytes
SHA-256: bc356a75828530d63794414a37aec1ada7ddf857c8a18e8b051b76322d49598f