Malicious PDF — malware analysis report

Static analysis result for SHA-256 81a3ed5fa88e23d5…

MALICIOUS

PDF

84.0 KB Created: 2021-09-12 06:58:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-23
MD5: f1ed9ac38a061fd2a69eebbb20ab1207 SHA-1: 90d14bf7555a7d87f26e8c3fd2304d865ceb34ac SHA-256: 81a3ed5fa88e23d5e58a62bd2d799f5515140017a533d30b095630a842e26fa6
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 0.9985

Heuristics 7

  • 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.
  • 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://oniceh.ru/uplcv?utm_term=what+measures+a+location+north+or+south+of+the+equator PDF link annotation
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/jc0bsc8v5ps96g50386rmtnbbo/biwijuxavowunitumel.pdfIn PDF document text
    • http://www.dfdtrading.sk/ckfinder/userfiles/files/fizevowovux.pdfIn PDF document text
    • http://akbarestate.com/survey/userfiles/files/naxopelabimujunufebi.pdfIn PDF document text
    • http://zulassung4you.de/bilder/file/jimosamikofenofe.pdfIn PDF document text
    • https://mlspoland.co/files/file/94478613671.pdfIn PDF document text
    • https://garnet-medical.com/userfiles/files/pujejunepexalopoxulej.pdfIn PDF document text
    • https://7foro.exceltur.org/exceltur_nuevo/ckfinder/userfiles/files/turixodilezedijasajimet.pdfIn PDF document text
    • http://plovdivweek.com/app/templates/js/ckfinder/userfiles/files/rokaxoduvemikoribufufinol.pdfIn PDF document text
    • http://mesterteto.hu/userfiles/file/43795788911.pdfIn PDF document text
    • http://embeddedhr.com/ckfinder/userfiles/files/26406795348.pdfIn PDF document text
    • https://norservis.cz/files/files/36729756508.pdfIn PDF document text
    • http://auxerretv.com/content/public/file/sasofufemetunuseja.pdfIn PDF document text
    • http://suphammamnon.org/uploads/files/87388036991.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/16133b2a526a2c---fasuvamaduxilew.pdfIn PDF document text
    • https://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/f2518fa6f5543d61a0792be375729fec/kevegimowabopezak.pdfIn PDF document text
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/102e7e25511cddc5fecf45647eae6af2/gezadifiga.pdfIn PDF document text
    • http://ibookingkr.com/FileData/ckfinder/files/20210910_B05791EE3A8A7CDB.pdfIn PDF document text
    • https://eagleegg5k.com/ckfinder/triplebuserfiles/file/6977412775.pdfIn PDF document text
    • https://callmarkinvestments.com/callmark/files/32649073361.pdfIn PDF document text
    • http://bidadapatidar.com/userfiles/file/17597204511.pdfIn PDF document text
    • http://chafewyuok.handysociality.com/upload/files/lotutugikoralipetimuz.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_off0000e56d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE56D 10840 bytes
SHA-256: 3d2ea666b51f08a27effdd797537743518688adf047a4f3287beb5f4d9c791b9
font_01_sfnt_off0000fe41.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE41 16764 bytes
SHA-256: 8ff8e58e5e405811af512ffc6d9e18eb67cea24ff70307924fe2d48091ab1fd0
font_02_sfnt_off000129dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129DC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1