Malicious PDF — malware analysis report

Static analysis result for SHA-256 98bf7756767849d8…

MALICIOUS

PDF

88.9 KB Created: 2021-09-13 19:44:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e8b7cbbf372bdb498b72e1d0f5753022 SHA-1: 226646b73c5f2bbe9002f7118689b03a0e16a589 SHA-256: 98bf7756767849d8cca427b141b50a4c33647cb888d8a6e5497103233ce73d40
174 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also features numerous links to external URLs, many hosted on disposable domains, suggesting a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to download and execute a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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 https://xn--interpeas-r6a.es/upload/files/72326634327.pdf In PDF document text
    • http://support-cmu.com/filedata/file/19229221254.pdfIn PDF document text
    • http://chanhungcorp.com/images/uploads/files/6927453945.pdfIn PDF document text
    • https://ichapps.peaceofworld.com/ichapps/ckeditor-ckfinder-integration/uploads/files/toliwisiwowatujefunur.pdfIn PDF document text
    • http://keacg.com/upload/files/xowed.pdfIn PDF document text
    • http://tfh-filter.hu/_user/file/komirodozelijosikaxod.pdfIn PDF document text
    • http://lucidarepavimentimarmogenovaealessandria.it/userfiles/files/63752413768.pdfIn PDF document text
    • http://elandtour.com/FileData/ckfinder/files/20210908_AF0E21D0A13BFD30.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161337a9787c26---2699087049.pdfIn PDF document text
    • http://spellenindex.nl/images/uploads/15145380590.pdfIn PDF document text
    • http://www.vljainandco.com/userfiles/files/tesumaselane.pdfIn PDF document text
    • https://communeouchamps.fr/userfiles/file/81106461390.pdfIn PDF document text
    • http://vytvarnyobchod.cz/UserFiles/File/tarigipiwo.pdfIn PDF document text
    • https://appchecar.com/ckfinder/userfiles/files/tuvajebujo.pdfIn PDF document text
    • http://nineslash.com/user_file/file/tubovuf.pdfIn PDF document text
    • https://limpjet.com.br/wp-content/plugins/super-forms/uploads/php/files/13ee3e708cb17a23a0dd41ff7d09776a/zemokatagowuf.pdfIn PDF document text
    • http://neuchina.org/userfiles/file/12830783148.pdfIn PDF document text
    • http://goodlack.cz/userfiles/file/19089495406.pdfIn PDF document text
    • http://onelove.cz/file/53203221046.pdfIn PDF document text
    • http://penzionnakrizankach.cz/ckfinder/userfiles/files/53821258579.pdfIn PDF document text
    • http://wohntraumgmbh.at/47051257180.pdfIn PDF document text
    • http://daechienglishpark.com/ckfinder/userfiles/files/povasuzaxig.pdfIn PDF document text
    • http://copy2d.com/ftp/image/file/31185775200.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=android+circular+progress+bar+with+percentagePDF link annotation
    • https://mediacentre.aerlingus.com/js/ckfinder/userfiles/files/varisewenozududifagaxu.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_off0000f81d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF81D 16740 bytes
SHA-256: bf72590c4e543782c0cea566dcd6365daf5662d19d0ca6ff8985159c762561c6
font_01_sfnt_off000123a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123A7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013bbe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13BBE 11100 bytes
SHA-256: 249066c19470b500bdf275ae1eb9c1cd6317edd0c2ee732d5575945f22c7b7e6