Malicious PDF — malware analysis report

Static analysis result for SHA-256 b0a28d907a943c0f…

MALICIOUS

PDF

87.3 KB Created: 2021-09-07 08:08:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 04ff9970b5142c25c209e4d9371f5eb7 SHA-1: 5af9a2607e7cd1e9d2918d8750b8dd658129c443 SHA-256: b0a28d907a943c0fe5cd546bfa120226a063f633ccb719e1f276b2ae1a5d8716
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier strongly indicates maliciousness, and the heuristic firings suggest this PDF is part of a link farm. The primary purpose appears to be redirecting users to potentially malicious or SEO-manipulated content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 5

  • 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://regeneracion-capilar.com/wp-content/plugins/super-forms/uploads/php/files/5fb2fa776ee32d1886ac9f4d7a35b503/29367837905.pdf In PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e731df4bd1b---mopuledebogo.pdfIn PDF document text
    • http://chithanhplastics.com/uploads/userfiles/file/pabasila.pdfIn PDF document text
    • http://balashixa.inhome360.ru/admin/ckfinder/userfiles/files/xugifexubitovojevum.pdfIn PDF document text
    • http://gpba.ge/admin/ckeditor/ckfinder/userfiles/files/kinemulosurilibe.pdfIn PDF document text
    • http://warraichmeats.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c973e0cc92---gogonavuwogibezenonisu.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/160de1fc93cff6---rurutafiferubusuwalatedam.pdfIn PDF document text
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/1606dc6811e0f7---85944778073.pdfIn PDF document text
    • http://pusheng168.com/uploadfiles/20210802041955.pdfIn PDF document text
    • https://daluxerealty.com/wp-content/plugins/super-forms/uploads/php/files/bivsl2p5s46p7q977ookughtd7/22350107001.pdfIn PDF document text
    • http://jinshi66.com/uploadfiles/files/bafotuxogutud.pdfIn PDF document text
    • http://alwaysfavorentertainment.com/clients/879371/File/nebemere.pdfIn PDF document text
    • http://poetische-malerei.de/web/editor/files/82363845224.pdfIn PDF document text
    • https://implant-drill.com/userfiles/file/wuzezapapibug.pdfIn PDF document text
    • http://rotarycochinharbour.org/ci/userfiles/files/sefetunijaguxelubusi.pdfIn PDF document text
    • https://malimbe.africa/wp-content/plugins/super-forms/uploads/php/files/b6a7e43fc499c665ff8c76869e25d57a/51390668472.pdfIn PDF document text
    • https://asharfilalkulfi.com/ckfinder/userfiles/files/lufutu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=difference+between+functional+structure+and+divisional+structure+pdfPDF 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_off0000f024.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF024 11008 bytes
SHA-256: a462b9aaceed21fe3de301c8bd93071f9912095c7d3ebd6d7f59b745a8e3abfe
font_01_sfnt_off000109b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109B4 17816 bytes
SHA-256: 78376e88afba1c29ae9f5059973787fdf9fb69f248537ebcdbf8eb0cdd8ad84d
font_02_sfnt_off00013748.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13748 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1