Malicious PDF — malware analysis report

Static analysis result for SHA-256 d9cd33720b0a6b39…

MALICIOUS

PDF

100.0 KB Created: 2021-09-24 11:27:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 31e80edada0da3ff1118adaeeda283a9 SHA-1: 1cb6aa6d9f42badf0096297462e5f0c20e937269 SHA-256: d9cd33720b0a6b393a8e14617a80baa204fde39c8c8daa83f0a5d95c66ab398a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. It contains numerous links to external websites, many of which are hosted on disposable domains or appear to be part of link farms, suggesting an attempt to redirect users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this. No scripts were extracted, but the overall structure and URL patterns are indicative of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9784

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://kursverwaltung.fit-n-essen.ch/ckfinder/userfiles/files/85075343397.pdf In PDF document text
    • https://bangprice.com/bangprice.com/beta/cms_image/file/wixepo.pdfIn PDF document text
    • http://www.juniorcollege.cl/ckfinder/userfiles/files/bavukixokivena.pdfIn PDF document text
    • http://flynewsletter.com/uploads/file/93825681187.pdfIn PDF document text
    • http://htbestcomputer.com/media/ftp/file/9504552461.pdfIn PDF document text
    • https://cupanghitam.com/contents/files/254432282.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613728cc80fa5---zivokatulavifasalamuf.pdfIn PDF document text
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1614a1860e1e56---julebirudut.pdfIn PDF document text
    • http://4darchitecture.org/img/all/75389684847.pdfIn PDF document text
    • http://4998horo.gmmwireless.com/contents/files/92975178006.pdfIn PDF document text
    • https://qualitygums.com/userfiles/file/51980295397.pdfIn PDF document text
    • http://bcslaw.hu/admin/fck_upload/file/6685106304.pdfIn PDF document text
    • http://affectif.ro/data/Image/file/ximivujejazupefetumes.pdfIn PDF document text
    • https://manhalhealing.com/userfiles/file/rupuxezi.pdfIn PDF document text
    • http://zeshengtecphar.com/UploadFiles/FCKeditor/20210901143539.pdfIn PDF document text
    • http://itemclinicchina.com/ckupload/files/soxidovo.pdfIn PDF document text
    • http://forti.in/userfiles/file/31924751323.pdfIn PDF document text
    • http://ominocoibaffi.it/userfiles/files/89560828967.pdfIn PDF document text
    • http://raczcsalad.hu/files/36311315073.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/gmqlhf7h271ppst01f435tlfsf/39108664022.pdfIn PDF document text
    • http://maslatalaia.com/userfiles/file/wiwenanugowida.pdfIn PDF document text
    • http://mottaing.eu/userfiles/files/40525078192.pdfIn PDF document text
    • https://storycycle.com/ckfinder/userfiles/files/1367190679.pdfIn PDF document text
    • http://inistor.com/ufiles/files/47090571149.pdfIn PDF document text
    • http://candleelectricals.com/uploaded_files/userfiles/files/26150371513.pdfIn PDF document text
    • https://chandrakantmusicacademy.org/ckfinder/userfiles/files/mibojalobibelixiju.pdfIn PDF document text
    • https://astoraccessories.com/uploads/ckfinder/files/xosexivaza.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=printable+40+days+prayer+for+the+faithful+departedPDF 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_off00011d0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D0F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00013521.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13521 19312 bytes
SHA-256: fe7a6d62adf967873f5b5401382c53db641ccdd160485f1ecaab1ed48fe57911
font_02_sfnt_off000167ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x167EE 11148 bytes
SHA-256: dc5e167f02c04853748cfa96b2fda9943083d159980f73740bb61915490516ca