Malicious PDF — malware analysis report

Static analysis result for SHA-256 41b355320d5783bc…

MALICIOUS

PDF

71.2 KB Created: 2021-09-12 03:58:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 40c3fe9d9cc9b7692deeaecbcb0a3528 SHA-1: d8e380ecaee58b00e74e2d24316815fe00206a39 SHA-256: 41b355320d5783bcf77d8701abd42d8933a9a49b3db69d8747b5b679ec67f75b
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier indicating a high probability of maliciousness. The file contains numerous embedded URLs, many of which point to compromised CMS upload storage or are structured as link farms on disposable hosting, suggesting an attempt to distribute malicious content or phish users. The presence of these link farms and the overall structure indicate a likely phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://onlinendttraining.net/files/doputeku.pdf In PDF document text
    • https://www.privathospitaletkollund.com/ckfinder/userfiles/files/juxokezosonurokajitaw.pdfIn PDF document text
    • http://nissanotogovap.com/uploads/images/files/21898267583.pdfIn PDF document text
    • https://egc.ecrom.work/syo/files/67553915784.pdfIn PDF document text
    • http://studiodispirito.it/userfiles/file/64487339060.pdfIn PDF document text
    • http://jun-travel.com/userfiles/file/zijopeko.pdfIn PDF document text
    • http://xn--80aafjbawrcdgsodbdciig4a5v.xn--p1ai/pict/file/91547127713.pdfIn PDF document text
    • http://ozkayalartrans.com/userfiles/file/633429477.pdfIn PDF document text
    • https://civilkontroll.hu/uploads/file/lewovawijovit.pdfIn PDF document text
    • https://pierrelemagicien.com/userfiles/file/rofiz.pdfIn PDF document text
    • http://capitolmetrophysicaltherapy.com/userfiles/file/34541903545.pdfIn PDF document text
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/81678382787.pdfIn PDF document text
    • https://himalmanpower.com/ckfinder/userfiles/files/43420315269.pdfIn PDF document text
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613346fe2d7c4---lugagomaditika.pdfIn PDF document text
    • http://mutitar.com/user_img/files/79350472065.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16130229bef6df---25186916812.pdfIn PDF document text
    • https://dm288.com/slicice/file/dexaxijug.pdfIn PDF document text
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613d3cade9c1e---21711250653.pdfIn PDF document text
    • http://bdsps.org/slbdavbatala/userfiles/file/selisufax.pdfIn PDF document text
    • https://threadworx.com/thread/admin/uploads/file/fexiwetebemumijozi.pdfIn PDF document text
    • http://sun-dr.com/uploads/files/202109041128548062.pdfIn PDF document text
    • https://datajournonepal.org/files/22816742295.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=free+fire+1.46+apkPDF 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_off0000b659.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB659 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ce6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE6B 16412 bytes
SHA-256: 7b5fd196a1808084c034220f9e6802a9b4dc8c38d62f891689509ad326030282
font_02_sfnt_off0000f8b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8B3 10248 bytes
SHA-256: a5159e038f0f63350f6c208cb93498d31c38b8a5f3b3f36551b0945739062386