Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac6ba8115a461541…

MALICIOUS

PDF

83.2 KB Created: 2021-09-01 10:52:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 5044ef9c6fd59fbe8bbd85cc63b24873 SHA-1: 8bb17d74b61cfcd127974caceed164c46b5d20ac SHA-256: ac6ba8115a46154132e93fa433e587e58cd4ae8986ec9e15f9eb37696171e639
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised WordPress upload directories and disposable hosting sites, suggesting an attempt to distribute malicious content or manipulate search engine results. The ML classifier strongly indicated maliciousness, and the structure of the PDF with numerous external links aligns with common phishing or malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://epilia.com/upload/FCKEditorfile/nunopabubupoduz.pdf In PDF document text
    • http://rhondadejean.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/ralimasobokexibatevuger.pdfIn PDF document text
    • http://eau-msu.ru/ckfinder/userfiles/files/96806735055.pdfIn PDF document text
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/161293432ef17e---87440192007.pdfIn PDF document text
    • http://goergenpainting.com/clients/0/0d/0d1038892961fdbf96b6a8e7e8daca8f/File/6950938836.pdfIn PDF document text
    • http://www.moyekolodin.com/files/vabepuzepeziradirupubinib.pdfIn PDF document text
    • http://funkyspa.net/ckfinder/userfiles/files/93387223493.pdfIn PDF document text
    • https://protrialse.eu/files/files/pipugedofapogi.pdfIn PDF document text
    • http://www.colormotion.cz/UserFiles/file/27292024141.pdfIn PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085615fc01d3---72642112676.pdfIn PDF document text
    • http://tai-yang.tw/taiyang/upload/file/19333924787.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/16080cc0965bfc---59437578512.pdfIn PDF document text
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a287ca73d6---puduzuretuzotivirijus.pdfIn PDF document text
    • http://xn--tnqz8hz5cb8l.com/upload/files/tefexesumu.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/e526rjeoevov0s70tijltv19i3/74185529660.pdfIn PDF document text
    • http://joyear.com/ckfinder/userfiles/files/85414708232.pdfIn PDF document text
    • http://byty-pardubice.eu/UserFiles/File/3199118540.pdfIn PDF document text
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607a2b7e2f1ed---kuvulaluxu.pdfIn PDF document text
    • http://musikpark-live.de/userfiles/file/50835607734.pdfIn PDF document text
    • http://stellamaris.cz/userfiles/22809276764.pdfIn PDF document text
    • http://kiavysocina.cz/UserFiles/File/kufabor.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a1f01f10f1---kesogeza.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=formula+to+get+total+costPDF 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_off0000dfd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFD3 18048 bytes
SHA-256: cd5e14496b84e93287bd470f4ac1900e31a234df87be06aabde38d3d686ede6a
font_01_sfnt_off00010e6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E6C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012683.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12683 10456 bytes
SHA-256: a4bc70a18b0d70843fbe12edc8c955d5919afc32863916e94a25ab9517333ac0