Malicious PDF — malware analysis report

Static analysis result for SHA-256 8850fc590cce6057…

MALICIOUS

PDF

87.2 KB Created: 2021-08-31 01:19:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: abb187736e3e376af724be2659712068 SHA-1: 7c9fd436a79fc7b65f071ec1b851b4c24c92f814 SHA-256: 8850fc590cce60577530fd0d52e2ea310de946a09564720f7063880c9c21256f
196 Risk Score

Malware Insights

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

The PDF document employs a social-engineering lure, instructing the user to install a browser extension or plugin to view its content. This is a common tactic to facilitate malware installation or credential theft. The ML classifier and ClamAV detection strongly indicate malicious intent, and numerous URLs associated with link farms and compromised CMS uploads were extracted, suggesting a distribution mechanism for further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://philabc.ru/uplcv?utm_term=struct+and+class+in+c%2B%2B PDF link annotation
    • http://effektfilm.de/files/file/dabilewobi.pdfIn PDF document text
    • https://visualarchive.bg/files/zupisodopemasewavutif.pdfIn PDF document text
    • https://xn--80aaijzh9b.xn--90ae/documents/file/84004937560.pdfIn PDF document text
    • https://dortmundpools.com/contents/files/27103869486.pdfIn PDF document text
    • http://cristal-in.fr/userfiles/file/gisurigegiraguz.pdfIn PDF document text
    • http://jrpst.pl/userfiles/file/19737011839.pdfIn PDF document text
    • http://fhhsclassof70.com/clients/4/42/42ce21dc30e429aa976ba070b22ccf93/File/35436997749.pdfIn PDF document text
    • https://dispomydeal.com/wp-content/plugins/super-forms/uploads/php/files/86c87db5719355daf2b298430464697d/69051475478.pdfIn PDF document text
    • http://hcvitamin.com/webroot/img/files/weteduperamovulup.pdfIn PDF document text
    • http://lighthouseofworship.com/clients/44803/File/lexumuwebadumosazox.pdfIn PDF document text
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/16083e8136d660---15087465422.pdfIn PDF document text
    • http://musicfriend.vn/public/default/ckeditor/files/56163459485.pdfIn PDF document text
    • http://yalcinsezer.com/upload/ckfinder/files/6163284067.pdfIn PDF document text
    • http://myhomeinparis.com/userfiles/files/39272187391.pdfIn PDF document text
    • http://obchodsezlatem.cz/upload/files/bopijipokujexusariwu.pdfIn PDF document text
    • http://kientrucnhacuagio.com/upload/files/77340640084.pdfIn PDF document text
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609555b60e411---pofekademebub.pdfIn PDF document text
    • http://ibshop.gr/uploads/_uploads/files/47335188229.pdfIn PDF document text
    • https://schmitz.cz/res/file/39591495753.pdfIn PDF document text
    • http://dailyxedayhang.com/userfiles/files/nolimi.pdfIn PDF document text
    • http://marta-galan.com/files/varios/file/guboxunezivosa.pdfIn PDF document text
    • http://rymwid-training.com/userfiles/file/fojajejepu.pdfIn PDF document text
    • http://attlas.center/userfiles/file/44598827322.pdfIn PDF document text
    • http://noavarservice.com/ckfinder/userfiles/files/mitonegamaralonave.pdfIn PDF document text
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160ae7c1e55fda---fogilatenudoxosedigexow.pdfIn PDF document text
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/c575032f5a1bdf6b626962d6f322f628/basevigefezuwumuvuni.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_off0000f0af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0AF 18016 bytes
SHA-256: 605999602c26f9681636a1ab41450861ddcc1ed220915459420cfb232248d501
font_01_sfnt_off00011ff8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FF8 10284 bytes
SHA-256: 8830635ae2550bbf4e9bd60ac63055aee18b1044fc2f43a9f6455e689993d069
font_02_sfnt_off00013728.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13728 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1