Malicious PDF — malware analysis report

Static analysis result for SHA-256 f31c7b2ce150c59c…

MALICIOUS

PDF

76.3 KB Created: 2021-10-21 04:16:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 0f69ef00baaffbe88a59e161bf4a345e SHA-1: b8d732ca1d8336c803107e52c9c9259c41a903a8 SHA-256: f31c7b2ce150c59c5eea1d3ca92eca4a02e9b69b60def67c46ca1edd50b32924
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as a link farm and potentially malicious, with a high ML score and ClamAV detection. The document body is heavily obfuscated, but the presence of numerous URLs pointing to compromised CMS uploads and disposable hosting suggests a phishing or malware distribution attempt. The primary attack pattern involves directing users to external malicious sites via embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://musicpark-live.com/userfiles/file/ratuseli.pdf In PDF document text
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ab66d3f3bf---relogasafudifuxobaw.pdfIn PDF document text
    • http://bloodfaces.de/attachment/file/94939271251.pdfIn PDF document text
    • https://icicle-mountaineering.ltd.uk/ckfinder/userfiles/files/rojakukibu.pdfIn PDF document text
    • https://pet-fashion.ro/mm/file/29207547019.pdfIn PDF document text
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/16130aa7c5459e---zanulewosalipetebufuzir.pdfIn PDF document text
    • http://good163.cn/Uploadfiles/files/49897772345.pdfIn PDF document text
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/0128121539f2ba0a4a2e82e7dc7d2b15/9098430495.pdfIn PDF document text
    • https://colakcivi.com/userfiles/file/31807476883.pdfIn PDF document text
    • http://metalzilembo.it/userfiles/files/64307331739.pdfIn PDF document text
    • http://wakabaeducation.com/userfiles/file/gebiwozufufunepufawevevi.pdfIn PDF document text
    • https://ms02bet.com/contents/files/95408475685.pdfIn PDF document text
    • http://zzzwchem.com/upload/files/31536114975.pdfIn PDF document text
    • https://lnpro.in/ckfinder/userfiles/files/fatupuxixemakosa.pdfIn PDF document text
    • https://cometgroupinternational.com/ckeditor/ckfinder/userfiles/files/kerofozela.pdfIn PDF document text
    • https://olamare.com/img/uploaded/file/gofudipulogez.pdfIn PDF document text
    • https://lerong.vn/wp-content/plugins/super-forms/uploads/php/files/e7f065bce95b85d139552cf095c18df5/kupatojovexefi.pdfIn PDF document text
    • http://awarelaxcentrum.cz/user_files/file/11792888086.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613dd0b61ca94---megezitotewusu.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/421e8ed9a0886e51db0e63b09effd42f/kidelokagadawanexupok.pdfIn PDF document text
    • https://073741256.com/uploads/files/202109032145006908.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/RhDyTiV0TgQ/uplcv?utm_term=what+is+traffic+regulationPDF 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_off0000c908.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC908 10708 bytes
SHA-256: cb8c39e57ddea888df0950b7efa20194691f7b100f415c5a8931238a7516faab
font_01_sfnt_off0000e1a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1A0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f9b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9B2 16296 bytes
SHA-256: b5ec32a55e63c8b97ffcc6e24457e51ed75a0e1f1973a488427177d4391d3109