Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1d021cf02ab7d96…

MALICIOUS

PDF

86.5 KB Created: 2021-09-10 04:15:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: cce68807e4b383b5226f02302eea7273 SHA-1: 37f7aaecfc98e41b67ab8678cef0f37fd4a1cfb7 SHA-256: c1d021cf02ab7d96bf8fda39ee259df99c8c679b5b51a681b642479f8f0e3b66
96 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs, many hosted on compromised WordPress sites or disposable domains, designed to redirect users. The ML classifier strongly indicated maliciousness, and the structure suggests an attempt to lure users to external content, likely for phishing or malware distribution. No scripts were extracted, but the overall pattern points to a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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://atx-stroy.ru/wp-content/plugins/super-forms/uploads/php/files/45d432e22da97be5c521c699ebce4ec7/kavadasepavuzezapox.pdf In PDF document text
    • http://thebookmarkcafe.com/uploads/files/82058221402.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138d6cc05064---23283633306.pdfIn PDF document text
    • http://czechnews.cz/userfiles/files/88891350334.pdfIn PDF document text
    • http://montpellier-businessplan.eu/mbp/upload/images/images/upload/ckfinder/21926050083.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1613a3106536e6---8186759447.pdfIn PDF document text
    • https://aluvioneschicamocha.sinecsas.com/ckfinder/userfiles/files/kukurirumowepukijuxogu.pdfIn PDF document text
    • https://razredna-nastava.net/files/verarimuzavipimezijazamu.pdfIn PDF document text
    • https://alebusph.centralcms.cloud/galeria/files/98379401307.pdfIn PDF document text
    • https://kovtec.pl/eurostyl/photos/file/setot.pdfIn PDF document text
    • https://asiantms.com/ckfinder/userfiles/files/xexalakozikosedewogole.pdfIn PDF document text
    • http://aksaxena.com/bpms/includes/fckeditor_uploads/userfiles/file/95231099982.pdfIn PDF document text
    • https://vibangnhadat.com/uploads/files/kulukikoxasewexojo.pdfIn PDF document text
    • https://client-sms.com/ckfinder/userfiles/files/mitebovagudumivugagob.pdfIn PDF document text
    • http://formpart.com/upload/ckfinder/files/68748351815.pdfIn PDF document text
    • http://kruengrangthai.com/files/files/90802918556.pdfIn PDF document text
    • http://mariamozharova.ru/uploads/files/64540150816.pdfIn PDF document text
    • http://glassick.com/userfiles/file/59320797430.pdfIn PDF document text
    • https://eldorado777.ro/upload/editor/file/kipot.pdfIn PDF document text
    • http://sungwoneng.com/upfile_editor/2021/files/dibujubikapuxiparulekire.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=moving+wallpapers+apps+androidPDF link annotation
    • https://tes-sys.com/uploads/ckfinder/files/20210901/16304722379395.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_off0000ed48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED48 10616 bytes
SHA-256: 84e8e31f91d574f5c27ea24f9414c8a8e9301174260df1caf23fc694f1923f60
font_01_sfnt_off00010583.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10583 17996 bytes
SHA-256: aeb9830e7f0f0df52248d84e518b213aa5f108dce2f263f559dd33d73266d330
font_02_sfnt_off00013432.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13432 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1