Malicious PDF — malware analysis report

Static analysis result for SHA-256 2491430aae103e02…

MALICIOUS

PDF

93.6 KB Created: 2021-09-17 23:33:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 48fa03fa798c7689d76f6be70f2ef8e4 SHA-1: 98cce364fd52e01f9bf53d2e5f73c918e5189b70 SHA-256: 2491430aae103e027cff2b8f4443d1983ac0fbe645dbff1c8a1054656b5524c4
156 Risk Score

Malware Insights

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

The file was detected as a malicious PDF by ML classifiers and ClamAV, indicating a phishing or trojan payload. It contains numerous links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest exploitation of PDF vulnerabilities to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9897

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://rayer.cn/d/files/91622761922.pdf In PDF document text
    • https://airflow-skateboards.com/userfiles/files/dolenalirorak.pdfIn PDF document text
    • https://ikansambel.com/contents/files/moxepewawapa.pdfIn PDF document text
    • http://darec.sk/files/files/figufuwukulodibironabu.pdfIn PDF document text
    • http://irina-beha.com/ckfinder/userfiles/files/rigelevenudo.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140e6dc7f3f5---nekimexoruru.pdfIn PDF document text
    • http://ssss-sangam.com/userfiles/file/gesimo.pdfIn PDF document text
    • http://www.ibadirect.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613418341f117---fanapuwitimepopajagopukep.pdfIn PDF document text
    • http://trovas.com/userimages/97540534199.pdfIn PDF document text
    • https://ibrahimkoc.com/images/Media/files/80812486815.pdfIn PDF document text
    • http://hanahana.vn/media/ftp/file/19009436724.pdfIn PDF document text
    • https://gianlucabruno.it/dati/upload/file/fugupifikitipafejiri.pdfIn PDF document text
    • http://fujieshubao.com/zk/UploadFile/file/2021091303002773499.pdfIn PDF document text
    • https://angkalaris.com/contents/files/1506751801.pdfIn PDF document text
    • http://www.taimaobi.com/admin/ckfinder/userfiles/files/82392666104.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161305a29a737d---wefemazoridugokezukopi.pdfIn PDF document text
    • http://moscreen.in/cmsfiles/file/devamadigasitu.pdfIn PDF document text
    • http://www.kizkulesikizogrenciyurdu.com/public/ckfinderuploads/files/67967751277.pdfIn PDF document text
    • http://kusistoconstruction.com/userfiles/file/nopisivagikotosigobip.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/13fb8ed64d4563c0d6b5b16d5d20f5f4/28009467602.pdfIn PDF document text
    • http://kaus21.com/userData/board/file/solotosesipumow.pdfIn PDF document text
    • https://cargotavio.ru/files/file/jagozilu.pdfIn PDF document text
    • https://cncunse.com/d/files/71826916686.pdfIn PDF document text
    • http://ykzn8.com/upfiles/editor/files/gitox.pdfIn PDF document text
    • https://tunguoilon.tunhua.vn/ipp/images/uploads/files/sozexabebekedepugux.pdfIn PDF document text
    • http://verzorgingsindex.nl/images/uploads/60403776948.pdfIn PDF document text
    • http://skoleniridicubrno.cz/ckfinder/userfiles/files/sosemikaw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=hematoma+massage+contraindicationPDF 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_off00010874.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10874 10656 bytes
SHA-256: 11f6c29e00e9093d37aec0b445301e54b0acd8f2682b1490c6a37eedc472d19f
font_01_sfnt_off00012095.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12095 17952 bytes
SHA-256: 750dbfc0ccc6abf4074eaa79b1a835509b865ff63b935e063f91d8b7b9eaa968
font_02_sfnt_off00014ed1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14ED1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1