Malicious PDF — malware analysis report

Static analysis result for SHA-256 4796437fdcb56e04…

MALICIOUS

PDF

89.2 KB Created: 2021-09-19 16:04:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 93efa5215409ae23544fede4fd2c3d9f SHA-1: 5488c595d9857f8f40cb30fe6bc38d18adbb52f9 SHA-256: 4796437fdcb56e04e197d9f7cf0350dabfe50abcf332580ea76e875fcbb3cce1
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 numerous domains, many of which appear to be compromised or disposable hosting. The ML classifier strongly indicated maliciousness, and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic confirms the nature of these links. While no scripts were extracted, the structure suggests an attempt to lure users to external sites, potentially for phishing or malware distribution.

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 https://slide-bearing.com/d/files/74822747232.pdf In PDF document text
    • https://gamma-electronics-eg.com/userfiles/files/11493692516.pdfIn PDF document text
    • http://paykaaluminiya.ru/ckfinder/userfiles/files/72314324467.pdfIn PDF document text
    • https://afgventuregroup.com/cfiles/file/vuluvunozarakebifovine.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/f8327cf2cc77ac01d99f8d62a2f0be50/puzanesed.pdfIn PDF document text
    • https://ustunbilgisayar.com/userfiles/files/14933373385.pdfIn PDF document text
    • http://taiwan-tsai.com/upload/files/73696182760.pdfIn PDF document text
    • https://www.bevillelecomte.com/ckfinder/userfiles/files/96540780740.pdfIn PDF document text
    • http://www.hgbehringer.de/img/files/files/ruperiluwekorek.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/161324b672bd1e---wasajelonajomadawosifanas.pdfIn PDF document text
    • https://typeone.com.my/ckfinder/userfiles/files/17876089808.pdfIn PDF document text
    • http://ablerexthailand.com/userfiles/files/73953317326.pdfIn PDF document text
    • http://ausafe.net/images/art/files/zaripunan.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16142699f78de7---bagodavirarufinovabitelo.pdfIn PDF document text
    • http://wonsakai.com/uploads/files/43872698143.pdfIn PDF document text
    • http://stihoplet.by/upload/editor/files/55303752988.pdfIn PDF document text
    • https://igruppe.no/ckfinder/userfiles/files/69699734968.pdfIn PDF document text
    • http://www.superior-inkjet.com/login/ckfinder/userfiles/files/rifokajagali.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/3e0b184ca372192c4ae620f1553e7c63/36209974988.pdfIn PDF document text
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/37cfc090968da52f695e61bf237b0992/87512746679.pdfIn PDF document text
    • http://haenuri.net/ckupload/files/96331889934.pdfIn PDF document text
    • https://pensionradvanice.cz/res/file/48351676312.pdfIn PDF document text
    • http://thebookmarkcafe.com/uploads/files/62849221522.pdfIn PDF document text
    • http://evevoyance.fr/adh/.-/file/nizewigorife.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=bios+ps3+androidPDF link annotation
    • https://www.posluh.hr/ckfinder/userfiles/files/29602982789.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_off0000f837.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF837 18436 bytes
SHA-256: e2c89ac209cccab49cfbb6577bd348aaec0ad52f716fbe91f004f1f57a3659a0
font_01_sfnt_off00012788.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12788 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013f9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13F9F 10336 bytes
SHA-256: 298a8af069dbb237de83f8bd7908592f7eae3da7063a4fdf14a26bdeebaa2d40