Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbd3afa6572f809e…

MALICIOUS

PDF

82.6 KB Created: 2021-08-17 13:41:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 2f6963c54c39956f457146da5b0e99a7 SHA-1: f1552478d8c6c197c69e06736fdfd425e189fa6c SHA-256: cbd3afa6572f809ebb3f489935f1b094ccf0fa6d20881938a0f8c23e2104ee60
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories. The ML classifier strongly flagged this PDF as malicious, and the heuristics indicate it functions as a link farm. While no scripts were extracted, the primary function appears to be directing users to potentially malicious content hosted on compromised websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://www.winsum.frl/ckfinder/userfiles/files/lomer.pdf In PDF document text
    • https://pluviaterra.mx/wp-content/plugins/super-forms/uploads/php/files/6618183c78a7315ba074abe7377c28b5/6128337338.pdfIn PDF document text
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1608fb2fcb747e---rufolalaxiwonili.pdfIn PDF document text
    • http://taxicityplus.ru/userfiles/file/joleroxunido.pdfIn PDF document text
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/61b323d91b15d1561e8873db7f479e58/movatulotorabomotetoxen.pdfIn PDF document text
    • http://siltherm.com/ckfinder/userfiles/files/78437860299.pdfIn PDF document text
    • http://jr-bang.com/uploadfiles/20210621022030.pdfIn PDF document text
    • http://philippinesroadshow.com/wp-content/plugins/super-forms/uploads/php/files/3f8645ce9ca4e074231f107ac89b52f9/wufibot.pdfIn PDF document text
    • http://radiosalsa.fr/php/rs/filesupload/file/76324761040.pdfIn PDF document text
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/jjeovu0cpct0kgjbhn6tivpsms/bixavapuxepemojuvonimuz.pdfIn PDF document text
    • http://theclubburger.com/uploads/files/94879270631.pdfIn PDF document text
    • http://purpledoorchurch.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a2f82ca5db---lisenazipejuminuma.pdfIn PDF document text
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afd31e7111a---56157203522.pdfIn PDF document text
    • https://sdudyogtechnologies.in/ckfinder/userfiles/files/wigukanefime.pdfIn PDF document text
    • http://msinziniering.com/userfiles/file/36830427541.pdfIn PDF document text
    • https://okinawa4d.com/contents//files/kodetinevileniwujewexod.pdfIn PDF document text
    • https://consultingexpert.eu/fckeditor/userfiles/file/modugofov.pdfIn PDF document text
    • https://rosewoodcity.org/nbloom/fckuploads/file/27895235145.pdfIn PDF document text
    • https://memoservicesrl.it/file/97061912091.pdfIn PDF document text
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ffa91d3649---moketojugetelituwoxuz.pdfIn PDF document text
    • http://greddy.com/admin/common/ckfinder/userfiles/File/vuzebudiwodukup.pdfIn PDF document text
    • https://alutat.com/data/file/37577164676.pdfIn PDF document text
    • http://elcwma.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/61281817355.pdfIn PDF document text
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/cd632fef875d6be2ea60d39862320cf4/xifulitogevafazuxidap.pdfIn PDF document text
    • https://bucatariizidite.ro/printuri-fi/files/37116914853.pdfIn PDF document text
    • http://nextgt.eu/uploads/file/foxonunav.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=what+is+the+difference+between+empathy+and+sympathy+in+counsellingPDF 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_off0000dbe2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBE2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f3f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F4 16984 bytes
SHA-256: 04e7c5e1e93186390412a2cb384b967fca276821e790e41db78d8393057d7388
font_02_sfnt_off00011f1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F1B 11500 bytes
SHA-256: 83714d912203a025599a2ef08316d46c6e327e876dfff768e221dfc4e26dbff4