Malicious PDF — malware analysis report

Static analysis result for SHA-256 db92db1749428a4f…

MALICIOUS

PDF

68.2 KB Created: 2021-09-27 16:18:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 532bd537b7700f625e55a85dfb7919bf SHA-1: f5b5b23ed21615887f2dea8797ba4312450c78f5 SHA-256: db92db1749428a4f3242d9749cbba92474bf9c3511d5a4cb91dabf2bb4dd8255
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm or redirection scheme. The ML classifier strongly indicated maliciousness. While no scripts were extracted, the structure and URL patterns are consistent with techniques used to distribute malware or engage in SEO spam.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://laborke.ru/uplcv?utm_term=3d+rose+live+wallpaper+free PDF link annotation
    • http://nscenter.cn/upload/files/rexoji.pdfIn PDF document text
    • http://chandravanshi.com/userfiles/file/73836014744.pdfIn PDF document text
    • http://lecostationery.com/files/file/manezewo.pdfIn PDF document text
    • https://sakesushimn.com/userfiles/files/62684350468.pdfIn PDF document text
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/18c4076b5632ffcd4aaf1bc42fee4397/fasubuj.pdfIn PDF document text
    • http://suachuamaydemtien.biz/userfiles/file/pexavuzujakujumijogi.pdfIn PDF document text
    • https://castel.ro/userfiles/file/45681326591.pdfIn PDF document text
    • http://daithanhnam.com/upload/files/69884313049.pdfIn PDF document text
    • https://sd-olimp.hr/files/sefaxuxuxuxusafobavi.pdfIn PDF document text
    • http://zatuchlina.cz/upload/file/47702531411.pdfIn PDF document text
    • http://morecoredesign.com/images/imageUps/files/26158380560.pdfIn PDF document text
    • https://tootooair.com/FileData/ckfinder/files/20210919_B5F2011A727842E5.pdfIn PDF document text
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/sudadafalagonixo.pdfIn PDF document text
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d5e2e9e5de---41027953644.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/161517749c7b38---juxix.pdfIn PDF document text
    • http://teranor.com/ckfinder/userfiles/files/zebami.pdfIn PDF document text
    • http://bestforfishing.com/wp-content/plugins/super-forms/uploads/php/files/a60b18a54d45eb987cb3e8c8250772e7/zetomegesojukidobuzuzilat.pdfIn PDF document text
    • http://bangiyaparishadtoronto.ca/bpt/editor/uploadfiles/berokusobivef.pdfIn PDF document text
    • https://brincandoeaprendendo.com/fotosempresa/files/19754990992.pdfIn PDF document text
    • http://gonganmi.com/userfiles/file/tagedalulepuwebidem.pdfIn PDF document text
    • http://nemeckystrakac.sk/editor_uploads/files/seketozuvunadagat.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_off0000ac81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAC81 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c493.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC493 15300 bytes
SHA-256: df4abce4fa16b68d64a26c5f503630d0e688aabd8b83a1c4a33227fd49d76ae4
font_02_sfnt_off0000eb64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB64 10516 bytes
SHA-256: 8c953eaf8f7fa357e7c1f66a88b5f4232d5b78b861f0e99ebd786763cf9f92de