Malicious PDF — malware analysis report

Static analysis result for SHA-256 8855173f8cbfda9d…

MALICIOUS

PDF

76.2 KB Created: 2021-09-12 23:16:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c6e56ac5440b852ea681ef69daca94d2 SHA-1: 951b04dbc833bec0992d61497475e6fa77f99957 SHA-256: 8855173f8cbfda9dac1486ad8f9ddfd8899b7de12ef249d0a4c0c8f24666be3b
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for executing malicious code within documents. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded JavaScript likely redirects to external URLs, as suggested by the PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics, which are often used for phishing or to download further payloads. The sample's structure and heuristics point towards a phishing or malware delivery campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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
  • 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 http://pyramidplaster.com/file_media/file_image/file/64221670720.pdf In PDF document text
    • http://aaas.handyfriendship.com/upload/files/wofakugukijirebozuzitulon.pdfIn PDF document text
    • http://hit-air.pro/ckfinder/userfiles/files/zebufefex.pdfIn PDF document text
    • https://highrise.pl/file/44411153045.pdfIn PDF document text
    • http://www.pethouse.es/ckfinder/userfiles/files/89012018781.pdfIn PDF document text
    • http://sisparts.pl/zdjecia/fck/file/buzumuwuvolatesomurotoxon.pdfIn PDF document text
    • https://birgatour.mn/js/ckfinder/userfiles/files/kirupawitidusoxejowaj.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/steprm8plqug2agk1115v3icd1/wawopuvizepikawegodorero.pdfIn PDF document text
    • http://holdemigny.fr/ckfinder/userfiles/files/22488899876.pdfIn PDF document text
    • http://risorsaterra.it/userfiles/files/xukuwirabavenazufob.pdfIn PDF document text
    • http://balbu.eu/uploads/news/file/lebiwevu.pdfIn PDF document text
    • http://rocincorporated.com/domain.com/images/dynamic_pages/file/93284831781.pdfIn PDF document text
    • http://entryexpress.online/chapter_images/files/84562086634.pdfIn PDF document text
    • http://investinwielkopolska.pl/application/lib/ckfinder/userfiles/files/fireloxiweler.pdfIn PDF document text
    • https://brillimet.com/uploads/files/202109101948523694.pdfIn PDF document text
    • https://topinsolventa.ro/userfiles/file/88534121027.pdfIn PDF document text
    • https://autoskola-scp.com/files/netikosigipekol.pdfIn PDF document text
    • http://taispacedesign.com/upload/files/jinusoxol.pdfIn PDF document text
    • https://showdetango.com/bafa/userfiles/file/59685213493.pdfIn PDF document text
    • http://boathousebrokerage.com/userfiles/file/42964643547.pdfIn PDF document text
    • http://ctyrkolky-gamax.cz/data/dokumenty/lukatupabilexelulikomumud.pdfIn PDF document text
    • https://mobilieroccasion.fr/uploads/file/56599771248.pdfIn PDF document text
    • https://perfecthospital.org/ckfinder/userfiles/files/zuwupifatefegasokewe.pdfIn PDF document text
    • http://shinhwajudan.com/userData/board/file/xepuxapidaz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=bluetooth+5+apkPDF link annotation
    • 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_off0000c3b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC3B6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dbcd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBCD 10264 bytes
SHA-256: f7b8bc987b81b79302807c5ee242624462ebff8086366f981c4e179e2cb97cb6
font_02_sfnt_off0000f31d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF31D 18428 bytes
SHA-256: fcc0ba2a730bc5e0c7e0284a81fcc72389c6c8caabd3d5eb172e97c50f9cd2f2