Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf90bc68fd543a46…

MALICIOUS

PDF

71.4 KB Created: 2021-09-17 19:20:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 4c819f37fc00f735c58d247a3d6cc564 SHA-1: 0a448b118f70a88aafcdb0882b65c810aa177b50 SHA-256: cf90bc68fd543a462c94341eccc63bf44a843896e96b97c55baafa1b523f91ef
164 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links to external PDFs hosted on compromised or disposable domains, suggesting a link farm designed to distribute malware. The presence of a 'download button' heuristic further supports the lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://alternatifhirdavat.com/upload/ckfinder/files/86477075701.pdf In PDF document text
    • https://mmrh.myagenda.cz/pictures/editor/files/sotozewedopos.pdfIn PDF document text
    • https://sofupingame.com/calisma2/files/uploads/90444361232.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/refif.pdfIn PDF document text
    • https://fleschimmo.lu/userfiles/files/borez.pdfIn PDF document text
    • https://blugarden.eu/file/maludibupezademaluvafema.pdfIn PDF document text
    • http://fiumevivo.it/userfiles/files/5460236457.pdfIn PDF document text
    • http://propertiesforrent.com/userfiles/file///56388383386.pdfIn PDF document text
    • http://avesta-hmora.boj.se/uploads/userfiles/files/55928012527.pdfIn PDF document text
    • http://arablift.net/userfiles/file/tesexonituvogixuwi.pdfIn PDF document text
    • http://selfmadefilms.nl/userfiles/files/55486133273.pdfIn PDF document text
    • http://bhk-aindling.de/userfiles/files/vabugaginafuf.pdfIn PDF document text
    • http://finemetal-cn.com/upload/files/pugavelela.pdfIn PDF document text
    • http://xn--80aaffebba2apgigwiiececnggk9e4k.xn--p1ai/pict/file/45638527237.pdfIn PDF document text
    • https://zenmobile.in/jaipriyart/uploads/files/29515731433.pdfIn PDF document text
    • https://qnzar.com/files/77622763845.pdfIn PDF document text
    • https://ka-base.no/images_content/file/34106982777.pdfIn PDF document text
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1614103d91598e---30417207053.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/161379edd71611---7318439772.pdfIn PDF document text
    • http://cosmoscm.com/contents/files/66813148640.pdfIn PDF document text
    • http://citescolairedeledit.com/include/file/zedekosenutegagalinobizu.pdfIn PDF document text
    • http://debseven.net/UserFiles/File/16950738224.pdfIn PDF document text
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/161410d796649f---54503795905.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=mytv+app+firestickPDF 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_off0000b725.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB725 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cf37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF37 16044 bytes
SHA-256: bb3fa83fe21f9959a41871083de94be5454d704c5d8e55a7e529c5033cfeb121
font_02_sfnt_off0000f84c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF84C 10468 bytes
SHA-256: b58d47ec3af87a71aa15252d1d61f8e3ed9c8662fb6006d007bafa96470e56b9