Malicious PDF — malware analysis report

Static analysis result for SHA-256 3156be2e7be55dd9…

MALICIOUS

PDF

68.8 KB Created: 2021-09-18 11:22:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 3c42f64c542c98dd2493037a7e34bf2e SHA-1: 3b5d3cef4c4b9224f02dd817ae250f95c5b61e0d SHA-256: 3156be2e7be55dd98c91b952b1009251670ac77937582b1ce497d6dc3d473ff1
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains a large number of embedded URLs, many of which point to compromised CMS upload directories or disposable hosting. The ML classifier strongly indicated maliciousness. The primary purpose appears to be acting as a link farm, likely to distribute malicious content or phish users, as suggested by the 'utm_term=download+mms+message+android' parameter in one of the URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://catamma.ru/uplcv?utm_term=download+mms+message+android PDF link annotation
    • https://beldapromosyon.com/calisma2/files/uploads/wixuvugasixajodobaruv.pdfIn PDF document text
    • http://knuhpharm.kr/userfiles/file/20210917183458.pdfIn PDF document text
    • http://officegate.biz/admin/fck_upload/file/47272030876.pdfIn PDF document text
    • http://network-italia.it/file/859190956.pdfIn PDF document text
    • https://360clothing.in/home/www360cl/public_html/uploads/images/files/morutupotanawobajolodita.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16135f5ea51457---7956424215.pdfIn PDF document text
    • http://usagimatur.com/files/others/22222214319.pdfIn PDF document text
    • http://isystemlab.com/admin/ckfinder/userfiles/files/fobop.pdfIn PDF document text
    • https://colegiumaniucarei.ro/ckfinder/userfiles/files/mavoku.pdfIn PDF document text
    • http://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/e8332e485cf67ef0a74a88e613ae1c7f/dizefumeb.pdfIn PDF document text
    • http://silverspringabw.com/uploads/files/retidujafenafebadipiwen.pdfIn PDF document text
    • http://insuralead.com/userfiles/file/zebik.pdfIn PDF document text
    • http://geologicatoscana.eu/userfiles/files/vodedel.pdfIn PDF document text
    • http://mp-journal.com/media/file/62662361642.pdfIn PDF document text
    • https://currenwatch.myhost360.cn/file/upload/files/09-12-03-34-25-79.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614314edd0ec0---55378328231.pdfIn PDF document text
    • http://fst-uinsu.net/userfiles/files/wabokitax.pdfIn PDF document text
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/161404e7836a85---19006069699.pdfIn PDF document text
    • http://rewitex.pl/userfiles/file/kekeribegivavajozovetanuw.pdfIn PDF document text
    • https://www.luthier-auxerre.fr/ckfinder/userfiles/files/tigelu.pdfIn PDF document text
    • http://kartinatv.org/uploads/files/93588020507.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_off0000b0cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c8df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8DF 14600 bytes
SHA-256: 44ea490edd9d177b4b5375f41b84176ea996b7179a0c61e1aa34076b2e1ba58f
font_02_sfnt_off0000ed95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED95 10580 bytes
SHA-256: e68ca2c7b9a86f6fa27d354e52e711e8106c2b2e4403f8c796675de540ac442a