Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5581eb5f0504f1e…

MALICIOUS

PDF

75.3 KB Created: 2021-09-18 00:05:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 023dc5bba95cbbd780d333ec128e8e49 SHA-1: 49f3685cd203c460dc3fcd0776f9f1631e322e5b SHA-256: c5581eb5f0504f1eb98c60ab2ccf4a77f2492cce24bfd801cae591de73b2e10b
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external links, including one identified as a potential redirector with a 'utm_term' parameter. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The presence of a visual download button further supports a lure-based attack pattern.

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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=yts+yify+proxy PDF link annotation
    • http://intertermo.nl/userfiles/file/65214303325.pdfIn PDF document text
    • http://joyerialaplaza.com/ckfinder/userfiles/files/jubuzux.pdfIn PDF document text
    • http://studiobardinisrl.com/userfiles/files/64411585908.pdfIn PDF document text
    • http://nujhimachal.in/img/uploads/files/19328513934.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/toxolexurixuwo.pdfIn PDF document text
    • http://eldmsh1.ru/js/ckfinder/userfiles/files/97880159168.pdfIn PDF document text
    • http://zulassungsdienst4you.de/bilder/file/67291268216.pdfIn PDF document text
    • http://bouwbedrijfansing.nl/userfiles/file/moxijafufonenuzebafazi.pdfIn PDF document text
    • https://0924055971.com/uploads/files/202108312333092412.pdfIn PDF document text
    • http://startmatbaa.com/userfiles/file/xapolotoviwexuzebopito.pdfIn PDF document text
    • http://safiorida.nl/operatori/userfiles/file/28847360227.pdfIn PDF document text
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613140a5518b3---zubuvutitalam.pdfIn PDF document text
    • https://vaitinhdien.com/app/webroot/upload/files/xubexamemunamegon.pdfIn PDF document text
    • http://ketphatthinh.vn/upload/files/kodiwulalodakozimu.pdfIn PDF document text
    • https://vgi-vn.vn/app/webroot/img/files/dutabikafuxotapop.pdfIn PDF document text
    • http://bytip.net/filespath/files/20210901063556.pdfIn PDF document text
    • http://gelateriacool.it/userfiles/files/vovudawirinix.pdfIn PDF document text
    • http://iact2001.com/userData/board/file/gewozemomuvalasabedi.pdfIn PDF document text
    • http://vantaidongsaigon.com/uploads/files/vogoraxiwemokekomepep.pdfIn PDF document text
    • http://tamlaproject.com/userData/board/file/melanobipamijezowokeve.pdfIn PDF document text
    • http://transportdiverse.com/uploads/files/vatunaxifosemip.pdfIn PDF document text
    • http://bluecars.pl/userfiles/file/67771854652.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/db6r3eoveqi7klqq86cpgm2r02/35501397749.pdfIn PDF document text
    • https://baxsporthorses.com/userfiles/file/18633424108.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_off0000c708.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC708 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000df1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF1F 10108 bytes
SHA-256: 7b7bbded3938f1067b21e5c02349117990c385092ab85195dba6e207ad9b757c
font_02_sfnt_off0000f5c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5C6 16572 bytes
SHA-256: a2ca2705a6e5605825e196ce35c37999019df15ec852bef44b54f67b9e7d1488