Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ea834f090b6a016…

MALICIOUS

PDF

69.2 KB Created: 2021-09-26 19:25:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 4dd17f7448685aaaa681dc35295d5b37 SHA-1: af82aab57f2c3003b0b8236f5425be27706f4516 SHA-256: 4ea834f090b6a016e4d1f761824ec70d87108ab89959a759d0453ba50a7dec44
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed for SEO poisoning or phishing. The ML classifier and ClamAV detection strongly suggest malicious intent. No scripts were extracted, but the presence of multiple suspicious URLs is sufficient evidence.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://trungnguyenjsc.vn/uploads/image/files/zevizupovatigumalujo.pdf In PDF document text
    • http://thaoduocvn.com/userfiles/image/file/544176435.pdfIn PDF document text
    • https://jechrina.gr/FCKeditor/userimages/file/43382524927.pdfIn PDF document text
    • http://burattinojatek.hu/userfiles/file/45017570542.pdfIn PDF document text
    • http://sqc.jp/user_data/editor/ckfinder/core/connector/php/upload/files/mibuxowomiladane.pdfIn PDF document text
    • https://oddluzanie.net/userfiles/file/84581920877.pdfIn PDF document text
    • https://fidelishospice.com/ckfinder/userfiles/files/35553456523.pdfIn PDF document text
    • http://tznjl.com/userfiles/files/gawumonasodavupofi.pdfIn PDF document text
    • http://armanetti.com/images/90235874352.pdfIn PDF document text
    • https://kerryparsonsfoundation.org/media/file/wadasar.pdfIn PDF document text
    • http://lpxs168.com/filespath/files/20210909004416.pdfIn PDF document text
    • http://fitsiluet.cz/data/file/fufiriwopu.pdfIn PDF document text
    • https://rent-1.es/ckfinder/userfiles/files/70982221095.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614265161f554---kupifodur.pdfIn PDF document text
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/161470892e1c4e---70597862837.pdfIn PDF document text
    • https://hohsingfiber.com/ufiles/files/55549584627.pdfIn PDF document text
    • https://etest.vn/app/webroot/uploads/files/duwagumuzanijenum.pdfIn PDF document text
    • https://fruitssupplier.com/app/webroot/img/files/49175973353.pdfIn PDF document text
    • https://ud-hobby.com/images/Upload/file/98803960244.pdfIn PDF document text
    • http://makaeximworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/161439ea422ae2---49230135244.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/brkk11cu6gq3ta51fq47c9bhm6/feveguviwojuwixa.pdfIn PDF document text
    • https://dubigroup.com/admin/fckeditor/editor/filemanager/connectors/upload/file/sadatal.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16130077c43dff---tadujekagebarepe.pdfIn PDF document text
    • http://roletyhanarol.pl/files/file/49721727807.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=mortal+kombat+x+offline+apkPDF 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_off0000b074.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB074 15168 bytes
SHA-256: a9dd088f1d56a062a358c598e88a21fea6ac5959cbe59128e45cb92c737673c6
font_01_sfnt_off0000d6c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6C6 10676 bytes
SHA-256: f778c22e8c8ab00cc03ceb4f293199e0c3c5e80306e8164f199c7de98387234d
font_02_sfnt_off0000ef07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF07 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1