Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5f5538d73ac4b3c…

MALICIOUS

PDF

70.4 KB Created: 2021-09-26 21:49:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 69706eb267f992f2af5961da295a30fc SHA-1: 1b5fd55469be4d3f27b2a801d1e606ceb8fcc7c8 SHA-256: f5f5538d73ac4b3c293fd8010c9fe21d437aab93ca2a32b9b532e31bd4c4b2f0
74 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by an ML classifier as malicious. It contains embedded JavaScript and numerous external URIs, many of which point to PDF files hosted on various domains. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a large number of links on disposable hosting, suggesting an attempt to distribute malicious content or harvest credentials. The embedded JavaScript likely facilitates the redirection to these external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 5

  • 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
  • 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://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/161493a16c91fb---watalibotalakememuwene.pdf In PDF document text
    • http://tubesealer.com/uploaded/file/213001170961503d5b9ea46.pdfIn PDF document text
    • http://kasargod.net/uploads/file/80989663338.pdfIn PDF document text
    • https://gentrilieu.vn/userfiles/file/wizipulula.pdfIn PDF document text
    • https://artedelvalle.cl/gal/files/file/95443577524.pdfIn PDF document text
    • http://ugrctrani.it/userfiles/files/lupaguwuzipabi.pdfIn PDF document text
    • https://livres-arts.com/ckfinder/userfiles/files/25569302920.pdfIn PDF document text
    • http://siltherm.com/ckfinder/userfiles/files/79067579216.pdfIn PDF document text
    • http://kpotplace.com/uploads/files/fobawunixofafisanaxak.pdfIn PDF document text
    • https://businessincasey.com.au/application/third_party/ckfinder/userfiles/files/31287955877.pdfIn PDF document text
    • https://learnrkb.jugalbandiresearch.com/ckfinder/userfiles/files/84379575444.pdfIn PDF document text
    • http://postelezmasivu-olomouc.cz/ckfinder/userfiles/files/40229784420.pdfIn PDF document text
    • https://ipekyolumedya.com/resim_galeri/file/22798854363.pdfIn PDF document text
    • https://enkaotomatikkapi.com/depo/sayfaresim/file/62472717573.pdfIn PDF document text
    • http://www.afamaresme.org/wp-content/plugins/formcraft/file-upload/server/content/files/16132a5c8e77b5---21105988653.pdfIn PDF document text
    • http://lexus-custom.com/js/upload/files/jaxafosizuwupipumesogugew.pdfIn PDF document text
    • http://sgadsahodayatarntaran.org/sahodyatarntarannew/userfiles/file/nisosavarejej.pdfIn PDF document text
    • http://finchamauto.com/pics/mejegox.pdfIn PDF document text
    • https://sbsoftware.ro/admin/userfiles/file/41438820373.pdfIn PDF document text
    • https://kalimati.in/userfiles/file/juvoduxefateziguxivetazo.pdfIn PDF document text
    • http://giasuthanhdat.vn/Images_upload/files/79532875389.pdfIn PDF document text
    • https://kurishupally.org/userfiles/file/sepogazirudepopu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=besar+un+angel+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_off0000b19d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB19D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c9af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9AF 16980 bytes
SHA-256: 4a9f1e8780e594689ec422ca09b744ec635aae6fe4df2cdcf6b39ff6ab157a97
font_02_sfnt_off0000f484.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF484 10516 bytes
SHA-256: 8288d277e821d4b790c6827e8d6854754857a44e88b25110d0637be7624880eb