Malicious PDF — malware analysis report

Static analysis result for SHA-256 16a156df1329b60a…

MALICIOUS

PDF

98.2 KB Created: 2021-09-09 13:53:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 805cfa748af2e23fd1f7eeb35e8904a3 SHA-1: 88251c115f207566f4737590c684b4698facb9f1 SHA-256: 16a156df1329b60ac75d9b336bb4328e75dc6497b8fac10a7be5f92403d9315a
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by an ML classifier as malicious and contains numerous external URIs, many of which are part of a link farm hosted on disposable domains. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of small PDFs acting as link farms on disposable hosting, suggesting a redirection or phishing scheme. No scripts were extracted, but the structure and URL patterns point towards an attempt to drive traffic to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 4

  • 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://laborke.ru/uplcv?utm_term=libros+de+ingenieria+quimica+pdf PDF link annotation
    • http://elesi.eu/fichiers/files/tesolidikutinojemed.pdfIn PDF document text
    • https://cleaner.pl/userfiles/file/gitimawetuzulilifadi.pdfIn PDF document text
    • http://stellar.ru/ckfinder/userfiles/files/nosan.pdfIn PDF document text
    • http://www.mattig-accounting.bg/fisiere/file/gurukilonejopezolesom.pdfIn PDF document text
    • http://www.saaegfpolis.org.br/ckfinder/userfiles/files/muxosuvotiw.pdfIn PDF document text
    • https://tttinox.com/upload/userfiles/files/91521994651.pdfIn PDF document text
    • http://smolensk-bakaleya.ru/userfiles/file/mizitedowafidu.pdfIn PDF document text
    • http://orthodoxvaidikasanghom.org/userfiles/file/kuxirifozifu.pdfIn PDF document text
    • https://tumujerrusa.com/userfiles/ligagebonajipata.pdfIn PDF document text
    • http://shyjjc.com/v15/Upload/file/2021951358321015.pdfIn PDF document text
    • http://konberdbio.com/upload/files/rajizejubimejegotokugo.pdfIn PDF document text
    • http://hoclaixebinhthuan.com/upload/contentFile/file/26800833925.pdfIn PDF document text
    • http://www.farmaciabergua.com/userfiles/files/16420419809.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613870453993b---76307068639.pdfIn PDF document text
    • http://ggmtc.net/userfiles/files/karijatesedesu.pdfIn PDF document text
    • https://praktijk-fix.nl/userfiles/image/file/68296350085.pdfIn PDF document text
    • https://wildarium.com/ckfinder/userfiles/files/6787022134.pdfIn PDF document text
    • https://vinadesigndanang.vn/uploads/image/files/bujozar.pdfIn PDF document text
    • https://www.abrasco.org.br/ckfinder/userfiles/files/gavikubedubibolebepija.pdfIn PDF document text
    • http://sevennews.com.br/ckfinder/userfiles/files/jujeboniw.pdfIn PDF document text
    • http://www.rosabrockenhaus.ch/ckfinder/userfiles/files/89104734510.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130278478d68---69665444706.pdfIn PDF document text
    • https://reazfarah.com/ckfinder/userfiles/files/deganojonezotonogura.pdfIn PDF document text
    • 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_off000110f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110F3 11160 bytes
SHA-256: ef612c51cb1d11da0a3a2af86d8ec36630dd2678014d2f2d9510e1e02c1720cb
font_01_sfnt_off00012a45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A45 21992 bytes
SHA-256: c4c50d5d832ed5fec6479491afbeac9a2036bad4d70edc7c448fa830d850a464
font_02_sfnt_off000162d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x162D8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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