Malicious PDF — malware analysis report

Static analysis result for SHA-256 13b46849f6c1c4f9…

MALICIOUS

PDF

87.5 KB Created: 2021-07-07 13:06:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c3d95bbddfd32a68ae2d2ccdd7e438ae SHA-1: 71be4927bc654453dc863dfd49cdb1fec3168ccc SHA-256: 13b46849f6c1c4f97257195d7e4ff341edbdc32a6ac897cd5d275f0194e5f08a
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised CMS uploads and disposable hosting, suggesting it is used for phishing or to distribute further malware. The presence of PDF-specific heuristics like PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://porpora.info/imagenes/imagenes_contenidos///69222070275.pdf
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/160a4bbd650564---gujubijegateziwu.pdf
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606fcaea14bf1---45424927237.pdf
    • https://idd.no/ckfinder/userfiles/files/96335944224.pdf
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dedb143f95b---36269536901.pdf
    • https://elpmarketing.ca/wp-content/plugins/super-forms/uploads/php/files/23eb17cfaf213e4130d411ec8c6c28f3/12110140281.pdf
    • http://bukhatirhomes.com/userfiles/file/62989502999.pdf
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16098b61197f04---36511510462.pdf
    • https://www.chesapeake-lighting.com/wp-content/plugins/super-forms/uploads/php/files/657a370bf31f842b7e5e7c08190d7544/49544013042.pdf
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/5a2bc22f6235cf8e0e4b3f098a3269dc/47398565411.pdf
    • https://www.carrentchiengmai.com/files/93654650865.pdf
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1609c28878b381---7025590789.pdf
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160bfca47c4f61---lebepujubo.pdf
    • http://sanitaerprofi.ch/fckeditor/editor/images/file/tifojas.pdf
    • http://autobedrijvenindex.nl/images/uploads/55800418134.pdf
    • http://www.marcado.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608046b0c5145---50443580023.pdf
    • http://clinicaveterinariailmarzocco.it/userfiles/files/jogubabi.pdf
    • https://argumentua.com/i/file/sugapokifotizisikuxijowe.pdf
    • https://demircanticaret.com/userfiles/file/juzemilafuduxivezazum.pdf
    • https://drsaman.com/files/5926477259.pdf
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c912c4aaa5f---sakite.pdf
    • https://hophamthaibinh.com/upload/files/90774705064.pdf
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa7be1769fc---wufabexepi.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=another+word+for+moves
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eed5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEED5 16792 bytes
font_01_sfnt_off000106e7.bin
a2c466d9d39f98aa7de900ae9e24a243f020117cffca617836cd948ae9d011b3
pdf-font-stream PDF embedded font (sfnt) at offset 0x106E7 19200 bytes
font_02_sfnt_off00013957.bin
1204db9f798beea11cd7d1226c3bd2447e3d01ca1da534a4efbecc5ee75189e4
pdf-font-stream PDF embedded font (sfnt) at offset 0x13957 10452 bytes