Malicious PDF — malware analysis report

Static analysis result for SHA-256 c0b94dba066bd9c8…

MALICIOUS

PDF

101.0 KB Created: 2021-09-10 18:16:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: ec8a3db60a00f6a54661fdd5878782bd SHA-1: a34ffce6c6dde16b88c456a42172c3147b6381d0 SHA-256: c0b94dba066bd9c877015ddb7938c6a3b634be79ca1823f4940943bac35bd929
156 Risk Score

Malware Insights

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

The PDF contains a link farm directing users to multiple external URLs, several of which are hosted on compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or to serve further malicious content. The document body is heavily obfuscated and contains no readable text, making it difficult to determine the exact lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://cuacuonnhanh.vn/Images_upload/files/60106334985.pdf In PDF document text
    • http://axwelindia.com/uploads/70365399042.pdfIn PDF document text
    • https://chrmglobal.com/userfiles/file/nogaxerenigupibi.pdfIn PDF document text
    • http://kcntanduc.vn/img_duhoc/files/93346782226.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613922674a3d6---25395651313.pdfIn PDF document text
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16137af7dbfb70---48232138757.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/gironeridenexepa.pdfIn PDF document text
    • https://www.alongsideasia.com/wp-content/plugins/super-forms/uploads/php/files/e11faf7f5ce3e8f51e9883facba9c6c0/32240828125.pdfIn PDF document text
    • http://fuzoku-kyujin.jp/ckfinder/userfiles/files/46912304940.pdfIn PDF document text
    • https://eksiliotomotiv.com/upload/ckfinder/files/luvelevulorikopamubure.pdfIn PDF document text
    • http://bdsps.org/slbdavbatala/userfiles/file/90915098521.pdfIn PDF document text
    • http://schokoladenfontaene.de/idata/tebanekinuwir.pdfIn PDF document text
    • https://bnbcostaverde.it/userfiles/file/59944724649.pdfIn PDF document text
    • http://fogathajtohirek.hu/fckfiles/file/toxuwoxijetovabufafubixo.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613acd5ca64b6---58268637580.pdfIn PDF document text
    • http://ctmmaximoravenna.com/ckfinder/userfiles/files/20729119170.pdfIn PDF document text
    • http://jgbt.us/pds/userfiles/files/68372297100.pdfIn PDF document text
    • http://mudrkanuch.sk/editor_uploads/system/files/xikagikikagigabulimukige.pdfIn PDF document text
    • https://bangvetthuong.com/luutru/files/46853964663.pdfIn PDF document text
    • http://abaj.cz/UserFiles/File/dopetojosuxopa.pdfIn PDF document text
    • http://phutungquanghieu.com/app/webroot/files/ckfinder/files/kivevirodafadiwolafi.pdfIn PDF document text
    • http://worldofpacifiers.com/editor_uploads/system/files/memaf.pdfIn PDF document text
    • http://jawarakreasi.com/file/97792413232.pdfIn PDF document text
    • http://kite-surf.sk/files/25421611575.pdfIn PDF document text
    • http://skinct.com/upload_file/file/Fl202109091436323800.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=vishnu+stotram+lyricsPDF 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_off00011a9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A9B 23268 bytes
SHA-256: 7fc99ef125ba9fe8ea6c1233d391e00af51f7b9c9aa4e3e5a31882e302368251
font_01_sfnt_off00015667.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15667 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00016e7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16E7E 10548 bytes
SHA-256: 6392e8a05bd01a6201d6a04f3f69f032518255294646683c3f5b17a3f30eed24