Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf51e7400e4083f4…

MALICIOUS

PDF

99.4 KB Created: 2021-09-04 09:46:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: fd6a22c5f2ae054960b8e3a7492dc4e4 SHA-1: 426572e95ebb3b6302bceb5a04ddeef2a5418e3f SHA-256: cf51e7400e4083f4dbf51e595ed60fa9f916f69e38d564f693f670f66cdafc35
164 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many hosted on compromised WordPress sites, suggesting a link farm or phishing lure. The presence of a 'download button' heuristic further supports the intent to trick the user into downloading a malicious file. ClamAV detection and ML classification confirm the malicious nature of the document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://medvor.ru/uplcv?utm_term=range+rover+sport+hse+2010+manual PDF link annotation
    • https://dipinkrishna.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c779e59876---lufuzuvomuxirukuratuxuses.pdfIn PDF document text
    • http://dailymaytrogiang.com/userfiles/files/27252229673.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/1607d5a40822e3---dagoropelevo.pdfIn PDF document text
    • http://www.centralperdana.com/file/tesula.pdfIn PDF document text
    • https://virtualpulse.eu/UserFiles/file/mopizotek.pdfIn PDF document text
    • http://shsalumniauditorium.org/clients/f/fa/fa32e32112b7cad64a7d7e78b95ed61b/File/76012026674.pdfIn PDF document text
    • https://sahyadrisevasanstha.in/userfiles/file/20331383273.pdfIn PDF document text
    • http://hotelamadeustorino.com/userfiles/files/nalukekojevebo.pdfIn PDF document text
    • https://perfecthospital.org/ckfinder/userfiles/files/24321845318.pdfIn PDF document text
    • http://srividyaastrology.com/userfiles/file/91321139147.pdfIn PDF document text
    • http://hilltop1976.com/clients/24685/File/bedakabidusu.pdfIn PDF document text
    • http://e-cluny.cz/UserFiles/file/49430541649.pdfIn PDF document text
    • http://agrobud.net/uploaded/file/jitenar.pdfIn PDF document text
    • https://cleanenergy.mn/uploads/files/70151968849.pdfIn PDF document text
    • http://chongqinghaohong.com/upload/files/15303176418.pdfIn PDF document text
    • http://sts-logistika.ru/wp-content/plugins/super-forms/uploads/php/files/00d38f0844a9cc5b6423d9b605f96318/92467669967.pdfIn PDF document text
    • http://ednak.com/wp-content/plugins/formcraft/file-upload/server/content/files/161068d759a076---gikakeb.pdfIn PDF document text
    • https://gruntbudowa.pl/files/file/89631671160.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085da0fa897f---73603793038.pdfIn PDF document text
    • http://dlzhrjd.com/images/uploadfile/files/jasafadit.pdfIn PDF document text
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/160a1900dab167---tugodigili.pdfIn PDF document text
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160740716f25ab---58573447845.pdfIn PDF document text
    • https://dsverano.com/UserFiles/File/rekimawepekiwabujisejot.pdfIn PDF document text
    • 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_off00011f5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F5C 11112 bytes
SHA-256: 2d8727266829a14dadc216c3a697443d849fcebe975b9472eacb973adf48d108
font_01_sfnt_off00013935.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13935 17912 bytes
SHA-256: 5f9bc6903e6eece1a38b719d219c4b9d140f0194f4f6776f2979f3d3b8502c3d
font_02_sfnt_off00016771.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16771 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1