Malicious PDF — malware analysis report

Static analysis result for SHA-256 16a898e57a32f783…

MALICIOUS

PDF

82.0 KB Created: 2021-09-08 11:52:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 527b6abad819f7f09eb2a5af992db789 SHA-1: 80e529fb56342bfbfc1b6714977ec8b256dd4883 SHA-256: 16a898e57a32f78397f72d3438344c874cf72f635305af8019b4efe74a500852
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. The file also exhibits characteristics of a link farm, with numerous URLs pointing to potentially compromised websites or disposable hosting. These links likely serve as redirects to phishing sites or for downloading further malicious payloads. The ClamAV detection and ML classifier further support the malicious nature of this PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 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.
  • 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://crewmak.ru/uplcv?utm_term=simple+sublease+agreement+pdf PDF link annotation
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac10eacd423---fazolusa.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c39ece6f032---wikodorazubukojefimurafur.pdfIn PDF document text
    • https://odontologosmalca.com/images/userfiles/file/53552230855.pdfIn PDF document text
    • https://fasleh.net/Files/files/wakijuwajeregotewitivem.pdfIn PDF document text
    • http://daivupaint.com/img-chamthi/files/62925816057.pdfIn PDF document text
    • https://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9a34fc1612---50592783885.pdfIn PDF document text
    • http://club-integra.ru/userfiles/file/99545224270.pdfIn PDF document text
    • http://denis-lefebvre-services.com/fichiers/file/ferixutizimutetebekotize.pdfIn PDF document text
    • http://computer-rudolstadt.de/upload/file/welozit.pdfIn PDF document text
    • https://ethiquedevelopers.com/wp-content/plugins/super-forms/uploads/php/files/0999782e455d6b63837c0d947f04f06b/zekezatumi.pdfIn PDF document text
    • http://www.assignproject.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f7fc93b95c---gaboxikifasejadenot.pdfIn PDF document text
    • http://security-m.jp/tool/images/file/menibanugavebu.pdfIn PDF document text
    • http://serextion2006.com/js/upload/files/84915894237.pdfIn PDF document text
    • https://baconbites.com/wp-content/plugins/super-forms/uploads/php/files/uqao4ann4gbnr8hdejodlajlg2/tezikumugabujuf.pdfIn PDF document text
    • https://x-software.cz/data/file/80507473445.pdfIn PDF document text
    • http://brandiassociati.it/userfiles/file/85720259477.pdfIn PDF document text
    • http://hornets88.com/clients/56662/File/ruzefowixoritamebemol.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/160abdb6e91f00---sijogedowunajobuxukigo.pdfIn PDF document text
    • http://euro-ex.com/images/blog//file/70932520612.pdfIn PDF document text
    • http://itkaufmann.com/images/fckimages/file/kivijijovikuzuzavi.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160876417816e9---20072968104.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/845bbe9e356dce6929215fbf261093f0/kigowudupaxavidotek.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609ed7ab40a68---42607346682.pdfIn PDF document text
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/f5caca47acbd69bc109d69796874b509/mofulepetot.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_off0000dd7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD7B 16864 bytes
SHA-256: 1d46d7ebe11b88a7f3ad3ec88863f59d642e92057bbf68451f667c8cedc50467
font_01_sfnt_off00010927.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10927 11036 bytes
SHA-256: c488ff1f04d04bae4b267dc612b731c090fe435ab46805560125ff234a788297
font_02_sfnt_off00012258.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12258 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1