Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a8136be49ab1d90…

MALICIOUS

PDF

76.5 KB Created: 2021-09-11 04:04:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 43cf7de2376c0085325c7c0cca7ccb22 SHA-1: ed19322550ec41e11668fb5c1decf0e44622bff3 SHA-256: 4a8136be49ab1d90f591bfed6e6520f63ffce2fc16c9f68c34e81bbe1c1028fe
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, pointing to multiple compromised or disposable hosting sites. The embedded URLs suggest an attempt to direct users to potentially malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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://rideabikenews.com/user_img/files/xaxida.pdf In PDF document text
    • https://visaonline-vn.com/wp-content/plugins/super-forms/uploads/php/files/nepql1flst6bn6h9p9qf0oiau9/66510847188.pdfIn PDF document text
    • http://obkladlazby.cz/userfiles/file/65894152498.pdfIn PDF document text
    • http://kenhuffbuilders.com/userfiles/file/mafizurezexituwog.pdfIn PDF document text
    • http://www.cenlafilm.com/siteuploads/editorimg/file/69206326229.pdfIn PDF document text
    • http://droneducational.com/admin/userfiles/file/pidimi.pdfIn PDF document text
    • https://rajatotogroup4.com/contents/files/47877371876.pdfIn PDF document text
    • http://internationalnetworksolutions.net/files/In PDF document text
    • http://yavuzselimvakfi.org/resimler/site/files/vifosubif.pdfIn PDF document text
    • http://shopgraeagle.com/ckeditor/uploads/files/fujaramopelik.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/5egpoq901refb7o6np2kgl9f06/7118082550.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/goselugodinubemapitemenef.pdfIn PDF document text
    • https://tutorbolivia.com/userfiles/file/jutenuzop.pdfIn PDF document text
    • http://tianfonmm.com/d/files/jifozi.pdfIn PDF document text
    • http://rhondadejean.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/26872620201.pdfIn PDF document text
    • http://grupposcorcia.it/userfiles/files/rekegemiparol.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/esjs1d3mqel8ro90qhhi62jsc2/91310813606.pdfIn PDF document text
    • https://esz.jp/img/editor/files/bikoxivasavejowa.pdfIn PDF document text
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/161374ae54e18e---41136991211.pdfIn PDF document text
    • http://cravaluos.com/ckfinder/userfiles/files/92234966488.pdfIn PDF document text
    • http://www.sarajevo-inn-grunewald.com/wp-content/plugins/formcraft/file-upload/server/content/files/161318cc3a71de---55953804167.pdfIn PDF document text
    • http://schodylux.pl/userfiles/file/82884650621.pdfIn PDF document text
    • http://brunagabriele.it/userfiles/files/43816583604.pdfIn PDF document text
    • https://pavillonwohlen.ch/userfiles/files/71882836265.pdfIn PDF document text
    • http://cistenivytahu.cz/upload/file/gerelegomilaxo.pdfIn PDF document text
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16138b3297e505---79618724890.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=play+minecraft+java+on+androidPDF 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_off0000c1f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1F9 18664 bytes
SHA-256: c86c0534cc6ac61c1eb24e2ea326c8fc8435698dc5521c5c2d64e465cfc5b3dc
font_01_sfnt_off0000f326.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF326 10780 bytes
SHA-256: 9055aed1d172d43570b5a3a436ad27f98c2bfc9efd7948b22010cb2a8f4a51cd
font_02_sfnt_off00010bf4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BF4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1