Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b7c8b7a27627699…

MALICIOUS

PDF

84.5 KB Created: 2021-09-17 09:24:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 9d902741e9a937cc9626cd165b070dff SHA-1: 935c7d9b12c1811f5be3dfc706d6989dcd0fa2e0 SHA-256: 4b7c8b7a276276992580253278809b6b89a361be2c9fc87c1f6a163fd041c115
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS uploads or are part of a link farm on disposable hosting, suggesting an attempt to lure users to malicious sites. The document body is heavily obfuscated and appears to be metadata from the wkhtmltopdf tool rather than user-readable content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 https://infosantiere.ro/userfiles/file/97096073074.pdf In PDF document text
    • http://kanchanaspa.com/ckfinder/userfiles/files/50326889294.pdfIn PDF document text
    • http://cuacuonnhaxuongbinhduong.com/upload/files/46826279370.pdfIn PDF document text
    • http://xn--vb0b83rba554gca.kr/page_data/file/20210902185740.pdfIn PDF document text
    • http://origo.ws/userfiles/file/kewoxipaxezuxedojaronajo.pdfIn PDF document text
    • http://antansconstructions.com/ckfinder/userfiles/files/tuboz.pdfIn PDF document text
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cf9256b4c4---33611226712.pdfIn PDF document text
    • https://betenenergy.com/sites/default/files/file/12584838018.pdfIn PDF document text
    • http://meruzhankhachatryan.com/app/webroot/files/file/76486314321.pdfIn PDF document text
    • http://phrabat.net/UserFiles/File/nizezemanogovapu.pdfIn PDF document text
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/161421da1c85d6---32904703853.pdfIn PDF document text
    • https://dichvumayphoto.vn/webroot/img/files/13489034071.pdfIn PDF document text
    • http://jcpingie.be/public/files/mopujikelitutoku.pdfIn PDF document text
    • http://cellesekorea.com/ckupload/files/68326652919.pdfIn PDF document text
    • https://bywuf.org/upload/editor/files/6857117017.pdfIn PDF document text
    • https://www.cdsale.org.au/application/third_party/ckfinder/userfiles/files/ratularuxuzezowelunizoso.pdfIn PDF document text
    • http://blesk-stroy.ru/userfiles/files/20117859582.pdfIn PDF document text
    • https://businesslife.com/content/file/72304122244.pdfIn PDF document text
    • https://muachungbaohiem.com/uploads/userfiles/file/febelizoza.pdfIn PDF document text
    • https://wildnaturetravel.com/File/pejijodawufej.pdfIn PDF document text
    • https://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/1613ff4f1aded0---kalurolo.pdfIn PDF document text
    • http://namngonviet.com/user-/files/2060868438.pdfIn PDF document text
    • https://profesa.net/userFilesfile/70793868664.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=shakti+13+january+2021+full+episodePDF 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_off0000dfde.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFDE 18860 bytes
SHA-256: 4c4bc0b2c4b94fe5799ad47e57a59692cccf787b46c1d625acf36850bcc50af5
font_01_sfnt_off000110e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110E5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000128fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128FC 11572 bytes
SHA-256: 84d3b69c3d352c10bc3bce342966bb2b8b9d4921f4e8a79ca1515531ee7b61b7