Malicious PDF — malware analysis report

Static analysis result for SHA-256 a0d557da5f8b0567…

MALICIOUS

PDF

90.2 KB Created: 2021-09-11 08:28:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 1ffdc6a34859d2cc891f7f1ed10ba53b SHA-1: aa810520d38702ecabd0f8cbbb7b55e7bce88eaa SHA-256: a0d557da5f8b05671ad52b26fe24f15a5dcd97f325146c93f08432a4a08d2139
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised or disposable hosting domains, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and the presence of numerous external URIs supports the conclusion that this document is intended to lead users to potentially harmful content. No scripts were extracted, but the structure and URL distribution suggest a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://ammk.sk/userfiles/file/kasepovuge.pdf In PDF document text
    • https://bistro-8.com/wp-content/plugins/super-forms/uploads/php/files/6ad0cb5bd4ca9c4a580a5024d003529b/11953683054.pdfIn PDF document text
    • https://cokhivietuc.com/img-vietuc/files/42201960689.pdfIn PDF document text
    • http://chulatutoracademy.com/chulatutor/ckfinder/userfiles/files/83636062619.pdfIn PDF document text
    • http://toshiteriyakiburien.com/uploads/files/70817208309.pdfIn PDF document text
    • https://lyonsinn.com/nbloom/fckuploads/file/medufuguwuzepagozolunido.pdfIn PDF document text
    • http://cosyromania.com/media/file/80108120912.pdfIn PDF document text
    • https://fong-cai.com/upload/files/fexakeremodemitixekesi.pdfIn PDF document text
    • http://avatars.ru/userfiles/file/pinitimedizemux.pdfIn PDF document text
    • http://zaragozalawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/57335082060.pdfIn PDF document text
    • http://tetobox-budapest.hu/uploads/files/tenemagegotokusebiwo.pdfIn PDF document text
    • http://kepco-group.com/uploaded_files/userfiles/files/10435672492.pdfIn PDF document text
    • https://olterus.com/contents/files/42764979221.pdfIn PDF document text
    • https://b2b-intelligence.it/uploads/file/melipefagasovazoxajal.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613923f43b14f---92625958378.pdfIn PDF document text
    • https://relaxbotanika.cz/ckfinder/userfiles/files/91427193870.pdfIn PDF document text
    • http://studiocommercialedelpiano.it/userfiles/files/toxanoxoradakupus.pdfIn PDF document text
    • http://ayhancevik.com/images_upload/files/15831304955.pdfIn PDF document text
    • https://yp05.com/_UploadFile/Images/file/bozabamusi.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1613967ff977f5---nonepigobivojusowek.pdfIn PDF document text
    • http://balashixa.inhome360.ru/admin/ckfinder/userfiles/files/kupazipafez.pdfIn PDF document text
    • https://rhodium.vn/uploads/news_file/32296916407.pdfIn PDF document text
    • http://southerncross-ex.com/images/blog/file/17395877699.pdfIn PDF document text
    • https://slicktechproducts.com/newerac2c/userfiles/file/57534915450.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=emulador+de+play+2+para+androidPDF 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_off0000f78d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF78D 10604 bytes
SHA-256: fe54c0155f385c5201dd4eef699d1afcd1bd91f9680e5fcdf0bf8e08f3617591
font_01_sfnt_off00010fad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FAD 19404 bytes
SHA-256: d1c337a01f0edd79ee750aa02036f18fb17682b1f80fe6c99a46cbc2767f15f3
font_02_sfnt_off000142b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x142B9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1