Malicious PDF — malware analysis report

Static analysis result for SHA-256 425905bdaba0b8b3…

MALICIOUS

PDF

70.4 KB Created: 2021-09-25 03:31:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: f72646636a724d11193bebdbc3237adf SHA-1: 19a58cc19104cfa8d41cf509afc3f2ded47e1719 SHA-256: 425905bdaba0b8b31e7fb6523624b265da9fde765df993f16442b95521a2d433
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS uploads. The presence of numerous PDF links and the use of 'utm_term' parameters suggest an attempt to lure users to potentially malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 6

  • 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.
  • 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=graphic+novel+techniques PDF link annotation
    • http://ephtour.com/FileData/ckfinder/files/20210905_DF5CE1EA83565006.pdfIn PDF document text
    • http://stavo-bazar.cz/userfiles/file/vosadivabowakanavo.pdfIn PDF document text
    • http://bayzones.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/13936644235.pdfIn PDF document text
    • http://www.abcklima.hu/data/editorfile/50440839520.pdfIn PDF document text
    • http://xn--ob0bjxt9h99icicrvkksa421cwwp7hiv4d6a.net/ckfinder/userfiles/files/manixar.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613a09e1bdf21---nugevumazela.pdfIn PDF document text
    • http://020tzs.com/baige/images/userfiles/file/vasiwawojojodute.pdfIn PDF document text
    • https://milorem-service.ru/userfiles/file/totifube.pdfIn PDF document text
    • http://naturabliskociebie.pl/userfiles/file/22995590554.pdfIn PDF document text
    • http://softtox.com/new/userfiles/file/26655315774.pdfIn PDF document text
    • http://csc-028.com/userfiles/file/20210905103842_g5yyl0.pdfIn PDF document text
    • http://massiimo.com/piceditor/file/23660953237.pdfIn PDF document text
    • https://www.medicalbi.com/ckfinder/userfiles/files/fanirixorop.pdfIn PDF document text
    • http://skkouty.cz/ckfinder/userfiles/files/ralon.pdfIn PDF document text
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/373227593099ed9f535e9d8623ec943d/wimomonawavajixi.pdfIn PDF document text
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/161360ebe4ed85---16440287385.pdfIn PDF document text
    • https://xn--i1aam8cb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/9e4a075ad8af46ea804f2c2e635efecf/46181644332.pdfIn PDF document text
    • http://www.synagoge-stommeln.de/ckfinder/userfiles/files/vubaxivufarixufax.pdfIn PDF document text
    • http://berbun.com/user_img/file/758454625.pdfIn PDF document text
    • https://schmitz.cz/res/file/rejideduxewuni.pdfIn PDF document text
    • https://hsdinstruments.nl/uploads/files/36513536522.pdfIn PDF document text
    • http://techbico.vn/uploads/image/files/29311052870.pdfIn PDF document text
    • http://maybomnuocdanang.com/uploads/image/files/mixad.pdfIn PDF document text
    • http://brickform.cz/obrazky/files/jenuzitepela.pdfIn PDF document text
    • http://siciny.eu/userfiles/file/26746920810.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_off0000b0cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0CB 16456 bytes
SHA-256: 48e1978219c0a66916ea9b42df081310444c45dee561a5b6abd09561785d6ab6
font_01_sfnt_off0000db1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB1C 10824 bytes
SHA-256: 79445e896d97ecdafc84f43532d1b9d6223fa617669984f2f0de1b2beb9deb70
font_02_sfnt_off0000f416.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF416 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1