Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3798ddd53e79b76…

MALICIOUS

PDF

87.5 KB Created: 2021-07-10 13:52:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 0efa7c83da70cc3bfb311c82f27c3452 SHA-1: b6829db3c4a4089d07139890eda09db6fb92b1d1 SHA-256: a3798ddd53e79b761d2a59bd30ef875fb21c99d74212a2987ff3eafed265d4be
156 Risk Score

Malware Insights

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

The sample is identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress sites, suggesting it's part of a link farm designed to redirect users to malicious content. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating the PDF's purpose is to host a large number of links on potentially disposable hosting. The ML_NYX_PDF_MALICIOUS score of 0.994684 strongly supports the malicious classification.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608f7266889e3---nogafajasususebudexus.pdf In PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/6b2876cf019bf5a51705c511da5d24c9/28853465702.pdfIn PDF document text
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160db7812c8115---nabixupitovuteragurupew.pdfIn PDF document text
    • https://burstallconrad.com/editor_files/file/79075825379.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c374a638f44---46147485464.pdfIn PDF document text
    • http://aimic.com/userfiles/file/nikepibuwaritigofi.pdfIn PDF document text
    • http://www.hypnotiseur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094fa7e36af5---rokilosut.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a30baf44cd8---dewev.pdfIn PDF document text
    • http://allamericannursing.com/userfiles/file/41471948971.pdfIn PDF document text
    • https://sckprime.com/wp-content/plugins/super-forms/uploads/php/files/2f08a28b71f66b47f1fa7685c3355fd0/64026342219.pdfIn PDF document text
    • http://canxetaidientu.com/images/file/narurawuxiwibezu.pdfIn PDF document text
    • http://agapetown.net/ckfinder/userfiles/files/teverutufuvanugivenibilep.pdfIn PDF document text
    • https://publicbridge.pl/userfiles/file/pisovikivokexoxo.pdfIn PDF document text
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/m5m28kj7kl3d61aungnq0afkkg/vofopafufovatef.pdfIn PDF document text
    • https://ohcsi.com/ckfinder/userfiles/files/77192094333.pdfIn PDF document text
    • https://goacetours.com/ckfinder/userfiles/files/13462392019.pdfIn PDF document text
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/160783d4dd6d95---87978692307.pdfIn PDF document text
    • https://teenvolunteer.org/wp-content/plugins/super-forms/uploads/php/files/0ed5953e1fdabc8c48d90d477add6edf/laregapure.pdfIn PDF document text
    • http://didaconcept.com/admin/fckeditor/file/58306042397.pdfIn PDF document text
    • http://www.alexgis.com/siteuploads/editorimg/file/fotajiwanebip.pdfIn PDF document text
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d802e22b3a0---48366011340.pdfIn PDF document text
    • https://fiambreszav.com/wp-content/plugins/super-forms/uploads/php/files/bc308eca9215ba8625efdc686113c5d8/senelawematozisefatus.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/1609aa3661e4f5---vuxivitalu.pdfIn PDF document text
    • http://promador.pl/userfiles/file/negisixoto.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=skin+lesions+associated+with+smallpoxPDF 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_off0000f378.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF378 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010b8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B8F 11032 bytes
SHA-256: d685c77b0f972cd8e9eb82e56d341bc0f8069aee2ab3d25a00f565c1c5e500ed
font_02_sfnt_off00012516.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12516 16648 bytes
SHA-256: d87812ae652d884eec0896e0d0c171814d32a26ae166d1e6b4097a7a4143c9e0

Open this report in the interactive analyzer, or submit your own file for analysis.