Malicious PDF — malware analysis report

Static analysis result for SHA-256 31a759476f514afc…

MALICIOUS

PDF

79.5 KB Created: 2021-09-19 15:25:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 345ce7affcfa8ee235bbe01d57cceedb SHA-1: 514a4ef0f81884c6b5afbb80901d31d3284cd103 SHA-256: 31a759476f514afc1d06b7b501e83a8daf9b36605d02fae0f0f787ba627e525f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links to other PDF files hosted on various domains, many of which are flagged as potentially compromised or disposable. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. The presence of multiple external links suggests an attempt to lead the user to malicious content, aligning with a spearphishing attachment tactic.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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
  • 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 http://angelofthewinds.net/ckfinder/userfiles/files/mejinowapumipavekobaxu.pdf In PDF document text
    • http://highlevel.pl/userfiles/file/nofamuxetu.pdfIn PDF document text
    • http://stsaischoolamritsar.com/slbdavbatala/userfiles/file/murigokadejatubazuwewumox.pdfIn PDF document text
    • http://global-leasing-management.com/uf/file/86473704502.pdfIn PDF document text
    • https://boumqueur-edition.com/upload/fckeditor/file/vejenab.pdfIn PDF document text
    • http://oticonshop.net/ckfinder/userfiles/files/wixukulifo.pdfIn PDF document text
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/d9bf4ad7da138940a787227d0e57a81d/gogino.pdfIn PDF document text
    • http://learningkey.org/userfiles/51169365547.pdfIn PDF document text
    • http://cantinachitarra.it/userfiles/file/lovajizolorerakuguvojig.pdfIn PDF document text
    • https://mmtours.si/uploads/zojofar.pdfIn PDF document text
    • http://nacyc.jp/Upload/file/jadozamavojemo.pdfIn PDF document text
    • http://business-plan-capalpha.eu/mbp/upload/images/images/upload/ckfinder/50207625952.pdfIn PDF document text
    • http://maschimaurizio.it/userfiles/files/82280122518.pdfIn PDF document text
    • http://sakesushilakehavasu.com/uploads/files/nepotetimufezefadosolu.pdfIn PDF document text
    • http://dglytbt.com/upfolder/e/files/20210905043749.pdfIn PDF document text
    • https://bamfieldrental.com/userfiles/file/37679037427.pdfIn PDF document text
    • http://ziguratex.com/helpdesk/app/webroot/img/userfiles/files/jafamemim.pdfIn PDF document text
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/76c92a43b6f75d17800833dc9ec7b234/nadexeba.pdfIn PDF document text
    • http://iranjobex.com/cache/fck_files/file/38005742366.pdfIn PDF document text
    • https://kar360.com/resimler/files/lixonekaripuvonubim.pdfIn PDF document text
    • https://cingenito.ca/upload/editor/file/foverubirobudutalobixikun.pdfIn PDF document text
    • https://www.hosotte.com/ckfinder/userfiles/files/minafewatodu.pdfIn PDF document text
    • http://piotrkowska77.pl/zdjeciafile/zipatotubazofoxikep.pdfIn PDF document text
    • https://globaltranslation.com/demo/global_translation/beta/userfiles/files/22517175141.pdfIn PDF document text
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161409e8fbe59f---58430056287.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=mtg+android+gamePDF 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_off0000d5d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5D3 16980 bytes
SHA-256: 3e793df08447acd8156db1e7e8116e0f18bc7ba69a65884e99290f4f74da73bc
font_01_sfnt_off000101a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101A1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000119b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119B8 10368 bytes
SHA-256: 8fcb4e970d0dc8ead30d48225b626aa1608fb33056847911ef54d250e01c327d