Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1596b9eb520ef11…

MALICIOUS

PDF

81.9 KB Created: 2021-09-15 15:17:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 69c3d738a5807eba9dbced5b77b07d08 SHA-1: 137dfa3104913f5deebdb03604fda8189c9e7dcb SHA-256: c1596b9eb520ef1101d6069ae3b9a1101b16a2dbf90d9e78bea2c9f0735a7d26
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to disposable hosting or compromised CMS upload storage. While no scripts were explicitly extracted, the PDF structure and embedded URLs suggest an attempt to lure users to external sites, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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 https://godparents4tz.org/home/god/public_html/ckfinder/userfiles/files/89944528296.pdf In PDF document text
    • https://safecampus.in/cmsCart/upload/file/sodizewedudejumawidotam.pdfIn PDF document text
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/51b7c42de399ece632ee7391a6de6f87/4875700792.pdfIn PDF document text
    • http://www.solarwindependence.com/ckfinder/userfiles/files/97515809663.pdfIn PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/uo3k19lm2r7c23ie5inn8vvboi/kanowesalopanekoxita.pdfIn PDF document text
    • https://funbugs.ie/userfiles/file/53843396379.pdfIn PDF document text
    • http://lukoilmarine.com/ckfinder/userfiles/files/44506412491.pdfIn PDF document text
    • https://prokoncept.hu/admin/blogfck/image/file/povijufulavumawimodezu.pdfIn PDF document text
    • https://perfecthospitals.org/FCKeditor/file/31226066555.pdfIn PDF document text
    • http://valentine.tutaylamhet.com/storage/ckfinder/files/gixusuxumomapazibogoma.pdfIn PDF document text
    • https://ruiguoex.com/upfile/files/2021/09/07/tokep.pdfIn PDF document text
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161319bbb2df0d---86794529728.pdfIn PDF document text
    • http://nagyberki.hu/sites/default/files/fck_uploads/file/naxubesufi.pdfIn PDF document text
    • http://technestudio.eu/userfiles/files/67750271560.pdfIn PDF document text
    • https://careerroots.net/ckfinder/userfiles/files/jetimezuser.pdfIn PDF document text
    • http://mos-craciun-inchiriere.ro/fckfiles/file/kaxodumabe.pdfIn PDF document text
    • http://balaton.varosom.hu/userfiles/files/xupaj.pdfIn PDF document text
    • http://ebrinteractive.com/userfiles/file/zawofilubowonadu.pdfIn PDF document text
    • http://tugrabilgisayar.net/resimler/files/nozivumafokoxugup.pdfIn PDF document text
    • https://sambelteri.com/contents/files/sapanogozaposus.pdfIn PDF document text
    • http://tandprotheses.com/ckfinder/userfiles/files/61652297591.pdfIn PDF document text
    • http://digitalpolicycouncil.org/imagenes/file/29499881673.pdfIn PDF document text
    • https://www.pessin-location.fr/ckfinder/userfiles/files/53967428876.pdfIn PDF document text
    • http://awfiowv.love-mrt.com/upload/files/32967315485.pdfIn PDF document text
    • https://roadtoring.com/wp-content/plugins/super-forms/uploads/php/files/b770ea62f4a4a8668f62334c22ceb03c/pimoxu.pdfIn PDF document text
    • https://vgi-vn.vn/app/webroot/img/files/ninowebobenoxevojulokuro.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=clr+via+c%23+2019+pdfPDF 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_off0000e0b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0B5 17160 bytes
SHA-256: 0c02e962a1033f5da9ab1244c1e59537d87a49d8fc8cfd26d166a6e47d6710b0
font_01_sfnt_off00010ded.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012603.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12603 9696 bytes
SHA-256: cbd35050cc2c2a875a1d8dd5a268f8ff7cee7227dc82adeadbc1a28586c25fca