Malicious PDF — malware analysis report

Static analysis result for SHA-256 834f3ae3a01c3976…

MALICIOUS

PDF

82.4 KB Created: 2021-09-14 10:18:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 52bd435b23a29d22a03732cf43c6dc5b SHA-1: 6be2621e2ffe9d9473af974c74fa9839c920a7e1 SHA-256: 834f3ae3a01c39765d3c179a3fc8f69687e6a8b3be751213e867765338f26a72
66 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various domains, with a high heuristic firing indicating it's a link farm on disposable hosting. The ML classifier also flagged this PDF as malicious. The presence of many distinct, potentially low-reputation domains suggests an attempt to manipulate search engine results or redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://panda-es.tokyo/yamituki-n/uploads/files/45066621531.pdf In PDF document text
    • http://designklasse.de/ckfinder/userfiles/files/35666160485.pdfIn PDF document text
    • https://jagamimpi.com/contents/files/63992784588.pdfIn PDF document text
    • http://www.its-dph.cz/admin/fckeditor/editor/userfiles/file/39894164999.pdfIn PDF document text
    • http://kleni.cz/userfiles/file/98192061139.pdfIn PDF document text
    • https://postelezmasivu-praha.cz/ckfinder/userfiles/files/tolerijewinebevod.pdfIn PDF document text
    • https://sakkestadbil.no/userfiles/file/73261080594.pdfIn PDF document text
    • http://toptoptraining.ru/img/upload/file/75539301021.pdfIn PDF document text
    • http://kavtas.com/images_upload/files/66519902804.pdfIn PDF document text
    • https://istanajpdua.com/contents/files/todogexodanerefulo.pdfIn PDF document text
    • https://limblength-sldf.com/userfiles/file/sazumupewixoloz.pdfIn PDF document text
    • http://terralis.eu/catalogue_dynamique/file/6555722282.pdfIn PDF document text
    • https://myphi.biz/nbloom/fckuploads/file/zuwesilixuvode.pdfIn PDF document text
    • https://billard-hauri.ch/userfiles/file/nufekobiwosuzemusebexi.pdfIn PDF document text
    • https://senesi-sklad.cz/userfiles/file/napiritibumujukefuvetav.pdfIn PDF document text
    • http://zkqzl.com/uploadfile/file///2021091405233724.pdfIn PDF document text
    • https://ppuhperspektywa.pl/files/edytor/file/60559764264.pdfIn PDF document text
    • http://ambulatorioveterinariorigolon.eu/userfiles/files/60781997205.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613743f007aa6---53299012950.pdfIn PDF document text
    • https://enkaotomatikkapi.com/depo/sayfaresim/file/97030635826.pdfIn PDF document text
    • http://gryfarmerskie.pl/pliki_wyswig/files/lorebuwomes.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161329d7321836---39425411294.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=samsung+galaxy+camera+phone+price+in+indiaPDF link annotation
    • http://s250801404.onlinehome.fr/img/uploaded/file/dubisowepuzurazawopupedo.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_off0000da2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA2A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f23c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF23C 18312 bytes
SHA-256: 4b902f2ed063bc4a5aeebf33fa8a814bf220a4d23bddfa4a7029f9700547c2af
font_02_sfnt_off000121ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121AE 11256 bytes
SHA-256: 8df11fe1451e50e14205513c14f0f98b4d3b8005c29661a6374c240bc4cb2623