Malicious PDF — malware analysis report

Static analysis result for SHA-256 bd5206bba88c8937…

MALICIOUS

PDF

82.4 KB Created: 2021-09-09 11:44:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 5c1f1f1257d47237cef57732ed5c1e91 SHA-1: 7bf9ac629a7694f08c643683b6e4922cf76589a5 SHA-256: bd5206bba88c893749a8a6ea21cb329fbab79167f1910d79549fedb9129976c2
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to suspicious PDF files on various domains, suggesting a link farm or redirection mechanism. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a tactic to obscure the true destination or spread malicious links across many domains. While no scripts were explicitly extracted, the nature of the embedded URLs and the overall detection suggest it's designed to lead users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://kuppersbusch.hu/userfiles/files/gigumexuzijubuwewolo.pdf In PDF document text
    • https://samsungdvmklima.com/upload/ckfinder/files/wizexuvewawezozorosese.pdfIn PDF document text
    • https://iqrainternationalschool.org/_assets/files/6825316886.pdfIn PDF document text
    • http://thepokeluau.com/uploads/files/41136273543.pdfIn PDF document text
    • http://soosanfix.com/upload/fckeditor/file/37504061180.pdfIn PDF document text
    • http://hidropro.hu/upload/3163210509.pdfIn PDF document text
    • https://baongochoa.com/upload/file/64719813011.pdfIn PDF document text
    • http://brkvinc.com/userfiles/file/tanidirezatufivazadusa.pdfIn PDF document text
    • http://imhang.com/fckeditor/userfiles/image/fuvaridoru.pdfIn PDF document text
    • http://martom24.pl/martom/userfiles/file/55464548856.pdfIn PDF document text
    • https://study-abroad-travel.com/ckfinder/userfiles/file/82997261900.pdfIn PDF document text
    • https://wildnaturetravel.com/File/64346094235.pdfIn PDF document text
    • https://ikitellirezistans.com/upload/files/gujiriveluxuxerata.pdfIn PDF document text
    • http://wx-test.com/upload/ckimg/files/202109041930439361.pdfIn PDF document text
    • http://www.chiringuitomediterraneo.com/ckfinder/userfiles/files/zerubunuluzedigamedawas.pdfIn PDF document text
    • http://winhazel.com/indigo/ckfinder/userfiles/files/jobuwafele.pdfIn PDF document text
    • http://nscenter.cn/upload/files/17017566747.pdfIn PDF document text
    • https://threadworx.com/thread/admin/uploads/file/79595004791.pdfIn PDF document text
    • http://ashole.hu/UserFiles/File/kotelum.pdfIn PDF document text
    • http://hc6999.com/userfiles/files/gomagovowit.pdfIn PDF document text
    • https://florerialafloresta.com/ckfinder/userfiles/files/44721428934.pdfIn PDF document text
    • http://yjbiotech.cn/upload/files/golakorega.pdfIn PDF document text
    • http://np-laser.com/upload_fck/file/2021-9-2/20210902203439164997.pdfIn PDF document text
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613726e416557---99918028989.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=solve+for+x+in+the+right+triangle+calculatorPDF 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_off0000dc9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC9E 10792 bytes
SHA-256: 4e90b69ab80c2487df102d07c1904fb58eb615077afca1f56fbffaf1c8d2dacc
font_01_sfnt_off0000f57e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF57E 17528 bytes
SHA-256: e9230b1eebc0d943354ab725c562b7c932d87344beac529305e6e2c3ed5d0e12
font_02_sfnt_off00012386.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12386 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1