Malicious PDF — malware analysis report

Static analysis result for SHA-256 c43e8a1cf5b0dcd0…

MALICIOUS

PDF

68.5 KB Created: 2021-09-19 19:32:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 81ccf6ba933e8b99002f38867ba0c9c7 SHA-1: 3000976fa0b4ad509a23f0be34952888a7701839 SHA-256: c43e8a1cf5b0dcd04cce72566a4ec81855a3d5f21fbdcd22f153733b43088af6
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to external files on various domains. Several heuristics indicate this PDF is part of a link farm, with some links hosted on compromised CMS uploads. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO abuse.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://debcopharma.com/userfiles/file/vezelevab.pdf In PDF document text
    • http://reguitti-engineering.it/userfiles/files/87625212604.pdfIn PDF document text
    • http://cropscipublisher.com/files/upfiles/file/36786430055.pdfIn PDF document text
    • http://tiszaikaland.hu/upload/file/zozomisizevugutelamasex.pdfIn PDF document text
    • https://mbbs.hr/files/gimirim.pdfIn PDF document text
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/1613f82b7772e0---bupatug.pdfIn PDF document text
    • http://www.ctmmaximoravenna.com/ckfinder/userfiles/files/32005678887.pdfIn PDF document text
    • http://myjobcareer.net/userfiles/file/2021091108471073499.pdfIn PDF document text
    • https://wasael.com/userfiles/file/83413676348.pdfIn PDF document text
    • https://samavetpharm.com/userfiles/files/82645324790.pdfIn PDF document text
    • http://tulga.ru/editor/files/94321481580.pdfIn PDF document text
    • http://pneusmarene.it/images/file/40423429761.pdfIn PDF document text
    • http://paraglider24.de/pics/fotos/1/file/jonidifururen.pdfIn PDF document text
    • https://melnikhouse.com/userfiles/file/fuzexedu.pdfIn PDF document text
    • https://www.lire-les-notes.com/ckfinder/userfiles/files/10276875806.pdfIn PDF document text
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613525709e1e7---97928985218.pdfIn PDF document text
    • https://juniorclublivorno.com/sitonews/images_upload/files/japipive.pdfIn PDF document text
    • https://www.ediliziaindustriale.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613efe805f309---81474426647.pdfIn PDF document text
    • http://esrafisek.com/images_upload/files/wevizujikebixasuzuguduxa.pdfIn PDF document text
    • http://gyogytornasz.hu/editor_up/98870986350.pdfIn PDF document text
    • https://propiedades.net/ckfinder/userfiles/files/kiterigixivedimokelosob.pdfIn PDF document text
    • http://lse.hu/userfiles/file/dusomex.pdfIn PDF document text
    • http://apexibd.com/uploads/fck_uploads/file/42108348345.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=gta+san+andreas+download+free+for+android+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_off0000af53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF53 14472 bytes
SHA-256: fea5612348298890a5e7af74b15567287b12251958191ba8cbde6fb2c994dadc
font_01_sfnt_off0000d386.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD386 10708 bytes
SHA-256: 059b099f6332de2b8191a8dc0e70fd7caf7cb54df1f9bf55c12e1210887b7f31
font_02_sfnt_off0000ec4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC4D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1