Malicious PDF — malware analysis report

Static analysis result for SHA-256 d84737a794320d1e…

MALICIOUS

PDF

70.1 KB Created: 2021-10-03 14:12:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: f4f3bb6038c1ad6298d095a11ae160bb SHA-1: 56bd1c8c277d5ddf30a36ce3b948f8fc042c9ca1 SHA-256: d84737a794320d1e2192a72ec56a10f9bd3065fa490d12374ed8ba9713633e3f
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 a link farm and by a machine learning classifier as malicious. It contains numerous external URIs, many hosted on compromised CMS uploads or disposable domains, suggesting an attempt to distribute malicious content or phish users. The ClamAV detection further confirms its malicious nature, identifying it as Pdf.Phishing.Trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://archism.ru/uplcv?utm_term=rate+formula+chemistry PDF link annotation
    • https://otterdisplay.com/userfiles/file/72903463904.pdfIn PDF document text
    • https://kurashi-kyoiku.com/cms/dat/upimg/file/57559301674.pdfIn PDF document text
    • http://studiomilano.eu/userfiles/files/48329878189.pdfIn PDF document text
    • https://aymexco.ro/ckfinder/userfiles/files/90551260182.pdfIn PDF document text
    • https://safewatersolutions.in/ckfinder/userfiles/files/16936158883.pdfIn PDF document text
    • http://rund.cz/UserFiles/File/pazutudugapotapixo.pdfIn PDF document text
    • https://www.groupe-coelho.fr/ckfinder/userfiles/files/piwisavi.pdfIn PDF document text
    • http://cgpharma.in/cote_dor_import/admin/ckfinder/userfiles/files/satonusororamajivesifiti.pdfIn PDF document text
    • http://pixel-pro.ru/upload/file/2149988199.pdfIn PDF document text
    • http://bidadapatidar.com/userfiles/file/23289206020.pdfIn PDF document text
    • http://smart.sut.ac.th/tsme/src/lib/ckfinder/userfiles/files/709783921.pdfIn PDF document text
    • http://talani.nl/userfiles/image/file/dizisor.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16148c88e317d2---napadopofetekixoz.pdfIn PDF document text
    • http://atrsara.ir/resource/files/bularis.pdfIn PDF document text
    • http://balletpanov.com/uploads/files/pisux.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16150b9036a84f---77024409972.pdfIn PDF document text
    • http://pcserviszlin.cz/ckfinder/userfiles/files/bilikegusikuxotenad.pdfIn PDF document text
    • http://ieeepes-thailand.org/app/webroot/files/files/venufusevimuranem.pdfIn PDF document text
    • http://ff-engineering.com/userfiles/files/gibudijaxivituxulete.pdfIn PDF document text
    • http://cbelmira.com/wp-content/plugins/super-forms/uploads/php/files/433b5d58fcd5134a3a7028d57997dba7/vugavamefipubiruru.pdfIn PDF document text
    • http://taxilitomerice.cz/ckfinder/userfiles/files/19191233046.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_off0000b07b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB07B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c892.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC892 10756 bytes
SHA-256: 6920835ae6feb23ccec05f22b498003f4a2ebd99e5e3b24e842862b5f9e18a33
font_02_sfnt_off0000e163.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE163 16488 bytes
SHA-256: 0a26487e9c17e85b1e5cbafdf01671ddce7d2a95f0212343976c74feb9d46311