Malicious PDF — malware analysis report

Static analysis result for SHA-256 b79d6fe005848394…

MALICIOUS

PDF

79.1 KB Created: 2021-09-12 02:00:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 3c985f0dee4773487ab0ebb889b9c273 SHA-1: 7f7ac3dcbc4cb037203298f8e4831f37f4d6a541 SHA-256: b79d6fe005848394171c14057ea78dfd96b4f1bc06a7493c89c52dd0e7f025db
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing numerous embedded URLs that form a link farm, with many pointing to disposable hosting or compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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://crysiq.ru/uplcv?utm_term=mod+legend+of+stickman PDF link annotation
    • https://sambelteri.com/contents/files/58716167605.pdfIn PDF document text
    • http://caogenzhiben.com/filespath/files/20210910152757.pdfIn PDF document text
    • http://tnslib.net/userfiles/files/27278200865.pdfIn PDF document text
    • http://gocoachfox.com/userfiles/file/56038572701.pdfIn PDF document text
    • https://cissud.com/uploads/ck_editor/files/gakipejixadazavaliduxi.pdfIn PDF document text
    • http://commune-bourre.com/userfiles/file/98627205472.pdfIn PDF document text
    • http://stefanourso.com/public/userfiles/file/wajagate.pdfIn PDF document text
    • https://www.burnat-provins.ch/ck/ckfinder/userfiles/files/jajazogol.pdfIn PDF document text
    • https://doitsolutions.co/wp-content/plugins/super-forms/uploads/php/files/550d6d703dfdb0b8fdc29564f9bdc733/xuxujasafemorogizikuba.pdfIn PDF document text
    • http://sial.pl/galeria/file/15380452318.pdfIn PDF document text
    • https://duhocblueocean.vn/ckfinder/userfiles/files/46030491222.pdfIn PDF document text
    • https://gullyracing.it/admin/ckfinder/userfiles/files/12701383863.pdfIn PDF document text
    • http://hanauhrova.cz/files/xopinidaluw.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/pavikuvusudilinubenox.pdfIn PDF document text
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/8ae9185689f8060907a363c3a13f1deb/84054088207.pdfIn PDF document text
    • https://balticstroy.com/uploads/files/lugedoxetubele.pdfIn PDF document text
    • http://mcrlclient.gilcom.ro/ckfinder/userfiles/files/tonopuze.pdfIn PDF document text
    • http://skoleniridicubrno.cz/ckfinder/userfiles/files/27158623488.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612fe0df937b7---doredisowokusinu.pdfIn PDF document text
    • http://de-ko-gmbh.com/ckfinder/userfiles/files/rusisilivejutededena.pdfIn PDF document text
    • http://fundacjahfg.pl/upload/file/86617789582.pdfIn PDF document text
    • http://sun-green.eu/ckfinder/userfiles/files/17525678703.pdfIn PDF document text
    • http://harlit.com/upfiles/file/11902846330In 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_off0000d1fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1FC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ea13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA13 10804 bytes
SHA-256: 67b54417dec8639b4bcb48a1cbba5ccd7a15004459afe7bff63fc2f7af53329d
font_02_sfnt_off000102c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102C7 17168 bytes
SHA-256: a31a1f57e0be1d8549422d182b8e7cc11164c63c319bd33c90e82b94c0ea1849