Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a73f7861eec7bbd…

MALICIOUS

PDF

84.0 KB Created: 2021-08-25 17:31:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-25
MD5: 27cbaaf8131dfe3a7ed8a6c44b707d6a SHA-1: ac90a5f10b9852b7ce9dff7c4ff39af78858c350 SHA-256: 5a73f7861eec7bbde91380196b8cbc877f2c7852035eba2f42eaa066907a61ba
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 0.9990

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=proverbs+in+sinhala PDF link annotation
    • https://phr4u.com/files/98529501691.pdfIn PDF document text
    • http://altaprecision.com/userfiles/file/303071988.pdfIn PDF document text
    • http://brmhn.com/userfiles/file/20210806184921_ic5jmg.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a691eb19335---toxedazokuwezutukedatula.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608402194e8f1---kobugap.pdfIn PDF document text
    • https://space1500.com/wp-content/plugins/super-forms/uploads/php/files/c6f2130ad9604b0fafd6ad03e17a49f8/pidikodigojes.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/b2f16bf502ae1d5cb8d0f3fadda39466/65102748991.pdfIn PDF document text
    • https://landtop.com/filespath/files/20210805171315.pdfIn PDF document text
    • http://cuacuondaiphuc.vn/upload/files/22468414968.pdfIn PDF document text
    • https://we-plus.tw/ckfinder/userfiles/files/23460319768.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/160c6e12f5d337---tiwutumanibaxe.pdfIn PDF document text
    • https://zlatartopalovic.rs//files/93712248400.pdfIn PDF document text
    • https://tecnibat.net/uploads/archivos/tuzobamupumoxasobivi.pdfIn PDF document text
    • https://www.peeryhotel.com/wp-content/plugins/super-forms/uploads/php/files/a9d453da11f54f4d82f61745e6dfc955/53660714159.pdfIn PDF document text
    • https://longislandinvestmentadvisors.com/nini/userfiles/file/pizujeruwiligejed.pdfIn PDF document text
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f914d9d049---motozegitadub.pdfIn PDF document text
    • http://biogenetec.tw/image/files/20210730_003032.pdfIn PDF document text
    • http://airconbank.com/upload/fckeditor/file/67103795091.pdfIn PDF document text
    • http://alfavs.eu/userfiles/file/47461181164.pdfIn PDF document text
    • http://chinhsuasolieu.com/media/files/62283760998.pdfIn PDF document text
    • http://myappartement.de/web/editor/files/62720995728.pdfIn PDF document text
    • http://www.pianoszimmermann.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607024c8750ff---kopizemulakodufi.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/ivfg5s1ctt05aos2jrmkhsh0dc/duvikotuzojexofuwi.pdfIn PDF document text
    • http://connect-senior.ch/uploades/userfiles/file/nigute.pdfIn PDF document text
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/f94b896915e7070a1dedeb0038740ca4/masaxipabibeva.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_off0000e28a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE28A 10316 bytes
SHA-256: 1df5ddea3c33360d3a771c886afa257648604aa8c8741757949ee7966ae0e94a
font_01_sfnt_off0000f9b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9B0 18064 bytes
SHA-256: 17523ef893e98b0c20e14351b03ece2b9f8e1ac8a57d1f3578ef08f5a88f776d
font_02_sfnt_off000127fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127FB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1