Malicious PDF — malware analysis report

Static analysis result for SHA-256 f94f6bfda0c1437e…

MALICIOUS

PDF

151.1 KB Created: 2021-09-11 10:29:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 23db82f693438dcf5ec0be92c9889b53 SHA-1: 540a5db33b22db0fbc3a91fb4479a52966e0ddae SHA-256: f94f6bfda0c1437eaacc98d18c2da2774d5e90b1aa59a38a8c1725dab60ae217
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 CMS upload directories or disposable hosting. The ML classifier strongly indicates maliciousness, and the link farm structure suggests an attempt to manipulate search engine results or redirect users to malicious sites. While no scripts were extracted, the PDF structure and URL analysis point to a malicious link farm, likely used as part of a phishing or SEO poisoning campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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://universalestetic.com/userfiles/file/62174101195.pdf In PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/161387ce01e323---vuzalogafefefitotejuka.pdfIn PDF document text
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139008d79ba0---22416349297.pdfIn PDF document text
    • http://www.badischer-kunstverein.de/ckfinder/userfiles/files/fumifositumoliwolaxe.pdfIn PDF document text
    • http://sns-russia.ru/userfiles/file/luseborimunatekiludiw.pdfIn PDF document text
    • http://bamboomfi.com/htdocs/cljr/data/files/51790966050.pdfIn PDF document text
    • http://105chers.netsociality.com/upload/files/wifefunuwekegukinezupot.pdfIn PDF document text
    • https://smartstone.ca/userfiles/files/19800308066.pdfIn PDF document text
    • http://mikllc.mn/uploads/files/jogaminisajap.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/161339c7cd132a---16375869531.pdfIn PDF document text
    • https://tlkingatlan.hu/kepek/other/file/43539018058.pdfIn PDF document text
    • https://alsharqcc.com/userfiles/files/wimipew.pdfIn PDF document text
    • http://northmarking.com/userfiles/files/jivix.pdfIn PDF document text
    • http://ecohost.ru/pics/images/file/talijujesapobawib.pdfIn PDF document text
    • http://gdlianyu.com/uploadfiles/file/81087373711.pdfIn PDF document text
    • http://www.ags-sib.ru/ckfinder/userfiles/files/36190247449.pdfIn PDF document text
    • http://engineersclasses4competition.com/files/others/48084795889.pdfIn PDF document text
    • http://rhondachem.com/d/files/mufewefufuk.pdfIn PDF document text
    • http://limoride.net/gallery/file/kirikudimefadawuxedanit.pdfIn PDF document text
    • http://galettedesrois.hu/userfiles/file/61852802661.pdfIn PDF document text
    • http://gz-theoutfit.com/UploadFiles/FCKeditor/20210906062718.pdfIn PDF document text
    • http://th-hl.com///upload/files/nosasoralamitavivin.pdfIn PDF document text
    • http://mcutech.net/files/22348677673.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=sons+of+behemat+battletome+pdf+freePDF 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_off0001ea3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1EA3B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00020252.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x20252 10884 bytes
SHA-256: fea23e2f55250cc448f7c2fe9bcedd04772e4f70466dff762a86110a5bca99aa
font_02_sfnt_off00021b11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x21B11 19748 bytes
SHA-256: 9e491090620269b3985e049a19e6ef8f5db146a759c928cba2e5263555b0aac0