Malicious PDF — malware analysis report

Static analysis result for SHA-256 33d1392978fdec77…

MALICIOUS

PDF

77.7 KB Created: 2021-09-18 14:59:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: a21c06d1c8a16bcb98c54d306f2a47a8 SHA-1: c85474c3ef2b1b9529966895afb051050b15831e SHA-256: 33d1392978fdec77a94991dbbccb2840d1e60bea1f1ab2c029c7de09e1af0677
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.6556

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • External URI info PDF_URI
    PDF contains an external URL action
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://slovbau.sk/test/userfiles/file/ronamovugunuvoge.pdf In PDF document text
    • http://montoaneli.com/ckfinder/files/fupazafivenuvovok.pdfIn PDF document text
    • https://hsse.hssanesteban.cl/files/xudowijiladelebazuxokefu.pdfIn PDF document text
    • https://marlin-aquarium.ru/ckfinder/userfiles/files/84237774370.pdfIn PDF document text
    • http://www.rosabrockenhaus.ch/ckfinder/userfiles/files/dogukasikigokunu.pdfIn PDF document text
    • https://onsale.social-push.cc/data/fckeditor/files/23792118063.pdfIn PDF document text
    • http://hstairan.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/49099520472.pdfIn PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/161451bd83908c---70041855221.pdfIn PDF document text
    • http://pekingtogo.com/uploads/files/mibuw.pdfIn PDF document text
    • https://nisahanpin.com/calisma2/files/uploads/jerojuwivamex.pdfIn PDF document text
    • http://hflbdq.com/uploads/file/081511068953.pdfIn PDF document text
    • https://www.mtiwelding.co.uk/admin/ckfinder/userfiles/files/lipafudada.pdfIn PDF document text
    • http://rovitek.com/userfiles/file/durovamimilaw.pdfIn PDF document text
    • http://musclecar-taps.com/js/upload/files/zibiwedajavuwujedufo.pdfIn PDF document text
    • https://mbzl-pro.xyz/web/img/podborky/files/37250314395.pdfIn PDF document text
    • https://aartipalette.com/userfiles/file/32789857985.pdfIn PDF document text
    • http://a-xian-coat.com/uploads/files/202109140047058922.pdfIn PDF document text
    • http://cuspsurgeons.com/userfiles/file/51907088382.pdfIn PDF document text
    • http://vanguardhungary.hu/userfiles/file/lobewutoj.pdfIn PDF document text
    • http://phutungvespaco.com/luutru/files/39107461374.pdfIn PDF document text
    • http://www.loicadesacavem.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16145a0cae3c41---70200077636.pdfIn PDF document text
    • http://vinmexindia.com/uploads/kexig.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613987ec3a6fe.pdfIn PDF document text
    • http://artpolinakuzina.ru/pict/file/43626667981.pdfIn PDF document text
    • http://kleinschadenexperte.com/userfiles/file/mopituwivuzolonazixa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=mx+player+pro+original+apkPDF link annotation
    • 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_off0000d506.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD506 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ed18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED18 19068 bytes
SHA-256: 8eadcb3f1744c02a86fb6f6201d2b7923556616afa716df03cbfbeb823e26e01
font_02_sfnt_off00011ebb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EBB 10460 bytes
SHA-256: cf975e21a4fe39bcaa3ecefcbf3a61376340128f67c5e0ed9d56b1067cfa5ca0