Malicious PDF — malware analysis report

Static analysis result for SHA-256 521f0a0e117d283e…

MALICIOUS

PDF

75.1 KB Created: 2021-09-03 21:06:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: c0f959b8791d3dcb5b36e038db5f78c1 SHA-1: cff1f03606c5b23c0a5082e14c437b26475068d5 SHA-256: 521f0a0e117d283e3a1b9379444aa11888295ec2757f5bdc7005996f5c39e4cc
96 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://philabc.ru/uplcv?utm_term=usability+engineering+at+a+discount+pdf PDF link annotation
    • http://teranor.com/ckfinder/userfiles/files/sinogugiduwopebulip.pdfIn PDF document text
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca1e86199e---6459022365.pdfIn PDF document text
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/af5e97e0ecae915e0def83ef1d7e8e57/lonumadibumepezeli.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5ad45bc548---basakavezuxorimudo.pdfIn PDF document text
    • http://ricarda-allegra.de/userfiles/file/guwumirad.pdfIn PDF document text
    • https://ewt.cz/res/file/vezitopabelokafi.pdfIn PDF document text
    • https://mtmnetwork.net/uploadEditor/files/20706153844.pdfIn PDF document text
    • https://cargobull.cz/res/file/39971653620.pdfIn PDF document text
    • https://hagakure.by/upload/editor/files/68063774513.pdfIn PDF document text
    • http://seowonbattery.com/files/fckeditor/file/11936130696123a980aeb45.pdfIn PDF document text
    • http://dichvutot99.com/webroot/img/files/juxajilakama.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607c535c63aa1---ribixezedamu.pdfIn PDF document text
    • https://espaciocultivarte.com/ckfinder/userfiles/files/pevewekimukaxinebid.pdfIn PDF document text
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/16093a63b76630---pazozejiji.pdfIn PDF document text
    • http://tachikawa-derma.biz/ckfinder/userfiles/files/gitezigetuturam.pdfIn PDF document text
    • https://digireg.ch/upload/61079094093.pdfIn PDF document text
    • http://lucchetta.net/userfiles/files/95426471854.pdfIn PDF document text
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/160af6f83d0b5a---sebetuxejivupepeze.pdfIn PDF document text
    • https://torbay.ru/images/uploads/file/wafunopasebanonimowavanaz.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607b3cc50a29c---fokofovabanogoki.pdfIn PDF document text
    • https://springkasteelhuren.be/userfiles/file/26506217159.pdfIn PDF document text
    • http://project-lovcen.me/userfiles/file/99221891512.pdfIn PDF document text
    • http://pomodorolennep.de/gfx/userfiles/files/86750549715.pdfIn PDF document text
    • https://narimasu-chintai.net/jcfiles/file/xezovamokisesix.pdfIn PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160947d5f27475---rodogofososevukujavipali.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_off0000c139.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC139 16820 bytes
SHA-256: 7ae70e37e1ceb5f2e531400b59565d79d60ea108de0b218a3b6b59e34adade94
font_01_sfnt_off0000ecc4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECC4 11156 bytes
SHA-256: 3b65aef379e7ec69c43d9290cbe9c8228b2f0a131fbcf2126d1eb1ec6be40575
font_02_sfnt_off00010695.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10695 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1