Malicious PDF — malware analysis report

Static analysis result for SHA-256 23aca66ae372c5ea…

MALICIOUS

PDF

84.0 KB Created: 2021-09-09 20:54:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: cb881224fcfc5f3de53c44ed1732a68c SHA-1: e4b2d03fc02e30ba5b97239070f49c1bb75afaf9 SHA-256: 23aca66ae372c5eae5e25b77517a6286f1d1e27d5a0ce100cffd0cad4c7ddb1a
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a large number of external URIs, many of which are hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests a deliberate attempt to create a link farm on potentially compromised or disposable hosting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://laborke.ru/uplcv?utm_term=hex+to+ascii+calculator PDF link annotation
    • https://www.liftechforklifts.com.au/application/third_party/ckfinder/userfiles/files/zijojarelaralumadisi.pdfIn PDF document text
    • http://baaningdoi.com/file_media/file_image/file/mumidus.pdfIn PDF document text
    • http://stjconsulting.it/userfiles/files/95261830142.pdfIn PDF document text
    • http://shinies.ru/img/lib/file/72052372133.pdfIn PDF document text
    • https://inprovitargentina.com/ckfinder/userfiles/files/94826181472.pdfIn PDF document text
    • http://terwaarde.be/ckfinder/userfiles/files/79832671375.pdfIn PDF document text
    • https://www.nstoplana.rs/ckfinder/userfiles/files/bivowetedupofo.pdfIn PDF document text
    • http://www.tecnologycenter.com/admin/uploaded/fck/file/tisotub.pdfIn PDF document text
    • https://funcarele.com/ckfinder/userfiles/files/23279065894.pdfIn PDF document text
    • http://alpinedelhi.com/userfiles/files/zubesorulinurokesarimu.pdfIn PDF document text
    • http://rustproofingottawa.com/userfiles/file/65876954834.pdfIn PDF document text
    • http://nasledie-sluck.by/var/upload/file/30545673490.pdfIn PDF document text
    • http://tiwtactic.com/userfiles/files/gofepexevizobobezageroza.pdfIn PDF document text
    • http://destockbaby.com/ckfinder/userfiles/files/83903002065.pdfIn PDF document text
    • https://kolegium.inaheart.org/upload/files/purezifi.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f8feea9d6f---34606698880.pdfIn PDF document text
    • https://fitness-sport.it/userfiles/file/58544229341.pdfIn PDF document text
    • http://sarica.com.tr/ckfinder/userfiles/files/fokosedopawalatapim.pdfIn PDF document text
    • http://trevelci.ru/ckfinder/userfiles/files/75751287621.pdfIn PDF document text
    • http://southerncross-ex.com/images/blog/file/16347967898.pdfIn PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/o8umb571q1k08dq2jc4284auoj/31947741297.pdfIn PDF document text
    • http://moyamoya.center/images/hand_uploaded/files/tudukarosebu.pdfIn PDF document text
    • http://www.ernakulamarchdiocese.org/www/js/ckfinder/userfiles/files/2823024971.pdfIn PDF document text
    • http://hoanggiaphatstone.com/upload/files/wuvuguzokanobojuvave.pdfIn PDF document text
    • http://ccsilver.kr/files/fckeditor/file/81553562161309b6ed2d01.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_off0000df0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF0D 19368 bytes
SHA-256: 86338391f48aeec1b565bd348a07d20d266e7145506fd6969d18595fbe9e179a
font_01_sfnt_off000112cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112CF 10312 bytes
SHA-256: c76d606710e384adea1f44c8ce70826a37739c16ff95999a9cdbba40acd9a82e
font_02_sfnt_off00012a30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A30 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1