Malicious PDF — malware analysis report

Static analysis result for SHA-256 34e52c9922b06f73…

MALICIOUS

PDF

68.0 KB Created: 2021-09-05 10:20:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: c6c3dd5f2a7d36f26bd9d32d9a5742b8 SHA-1: 1b714119a1baff0680f5e8f4bd4174244a0697de SHA-256: 34e52c9922b06f73c0abe64bf1f4ccda06c75fa1ecf8e789572e5bb8842361b0
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable domains. These URLs are likely used to redirect users to malicious content or for SEO spam. The ML classifier strongly indicated maliciousness, and the heuristic firings confirm the nature of the PDF as a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://crysiq.ru/uplcv?utm_term=prescott%27s+microbiology+8th+edition+pdf+online PDF link annotation
    • http://hk-dcc.com/wp-content/plugins/super-forms/uploads/php/files/itj9r6a1n1dm66jl5d9k0dq5ag/fesiwuwumasal.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb7a0d051f---33952759434.pdfIn PDF document text
    • http://boathousebrokerage.com/userfiles/file/sujupov.pdfIn PDF document text
    • https://lsp.od.ua/wp-content/plugins/super-forms/uploads/php/files/73mcfhmr6o9qepaebklkikfum0/zamizuvikononegon.pdfIn PDF document text
    • http://studioassociatoemc.com/userfiles/files/46367462531.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/16072e1ace8016---budodusililisedan.pdfIn PDF document text
    • http://rcmo.ru/upload/files/fezuzavaburul.pdfIn PDF document text
    • http://xedaptheduc.net/app/webroot/uploads/files/sisuriruj.pdfIn PDF document text
    • http://doks-films.com/pcms/content/file/gipitifubudulat.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609e192980984---92061699380.pdfIn PDF document text
    • https://crownprolaw.cn/userfiles/Proj_Name//files/12494459881.pdfIn PDF document text
    • http://k-yoga.org/file_upload/spaw_upload/file/20210516123626.pdfIn PDF document text
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d9d39982b2f---23989711140.pdfIn PDF document text
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/65jl97ab9g6djnu05v9micrrhn/83031313638.pdfIn PDF document text
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad8d5fa38de---lajixixenal.pdfIn PDF document text
    • http://hugslock.com/app/webroot/img/files/mumevafiripu.pdfIn PDF document text
    • http://smeclassof1987reunion.com/clients/37165/File/18828892087.pdfIn PDF document text
    • http://donationwebsites.com/clients/6/68/68901b9e08e997a22fc64c74502b39ca/File/nozukasexevi.pdfIn PDF document text
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1609ff14693b24---rigagagawogevokarazakabo.pdfIn PDF document text
    • https://tennis94.fr/img/pics/files/60337359185.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_off0000ac3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAC3D 11404 bytes
SHA-256: b3eeb9135875d22752d07b58c06ce95d8e80df00e8ea67c691fb7de077c17074
font_01_sfnt_off0000c697.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC697 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000dea9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEA9 14240 bytes
SHA-256: dcde6278bc0218b68064bf9e94ea318207a52bfb92351104496d03353b78c4d3