Malicious PDF — malware analysis report

Static analysis result for SHA-256 991756d16eadfa3f…

MALICIOUS

PDF

68.9 KB Created: 2021-09-26 05:05:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 94680360ecead52d7a1599a1b2480877 SHA-1: 15c1d2de2535328021e42ce82951dec07f08527b SHA-256: 991756d16eadfa3f1c954a10b31c0d8b3448740be32a5f39ec793d2a67e81469
96 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to various domains, many of which are hosted on compromised CMS platforms or disposable hosting, indicating a link farm or SEO manipulation tactic. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the structure and URL patterns suggest an attempt to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://tuhocxuatnhapkhau.com/uploads/ckfinder/files/zixakowi.pdf In PDF document text
    • https://ms2oke.com/contents/files/fetovusuwuxosaxupezuginow.pdfIn PDF document text
    • https://babetravelling.com/ckfinder/userfiles2/files/75783055796.pdfIn PDF document text
    • http://jedwines.com/cmsCart/upload/file/11937876336.pdfIn PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/1614b440a22deb---tesotegulubosikilesowovod.pdfIn PDF document text
    • http://homeopathyhk.com/files/31350921341.pdfIn PDF document text
    • https://hurghadalife.net/userfiles/files/pupobuxagexuko.pdfIn PDF document text
    • https://linkevicius.com/upload/galery/file/25613153678.pdfIn PDF document text
    • http://nuovojob.com/userfiles/files/kaxotinidamanevuxe.pdfIn PDF document text
    • http://tjsyjdq.com/v15/Upload/file/2021926626185826.pdfIn PDF document text
    • http://brunagabriele.it/userfiles/files/67370280160.pdfIn PDF document text
    • https://adikkedua.com/contents/files/xubijadogezo.pdfIn PDF document text
    • https://atavio.ru/files/file/xowubekarivup.pdfIn PDF document text
    • http://naplesredeals.com/userfiles/files/kerivot.pdfIn PDF document text
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/ecc9569975f27eda201b3d2719c2d5ff/58722674923.pdfIn PDF document text
    • http://www.biosafety.biz/ckfinder/userfiles/files/4981876512.pdfIn PDF document text
    • https://equimat-cheval.fr/file/45586441116.pdfIn PDF document text
    • http://cabanagarden.hu/editor_up/74030397275.pdfIn PDF document text
    • http://kagoshimakojintaxi.com/userfiles/file/32201620577.pdfIn PDF document text
    • https://www.intermediastudios.com.mx/wp-content/plugins/super-forms/uploads/php/files/941c6fce576e75b54c9a0a138d2e7fa9/78887257444.pdfIn PDF document text
    • https://alpinashop.bg/files/pogolabe.pdfIn PDF document text
    • https://ms2gacor.com/contents/files/zolevoremutupiselo.pdfIn PDF document text
    • http://dilimkebab.com/userfiles/file/fixevefexuboxibinipuje.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=how+to+change+font+on+redmi+note+9PDF 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_off0000ae9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE9B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c6ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6AD 15248 bytes
SHA-256: 79dba8daab260823ac1c87bb3f67045fccc7b7025683d3fe0743dda4a6102185
font_02_sfnt_off0000ed19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED19 10956 bytes
SHA-256: 97c712bca65909b9ac3a2c826c527b6417cc4055b8f06de3359b631068137272