Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4145c6f98c90165…

MALICIOUS

PDF

75.5 KB Created: 2021-06-23 13:18:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-23
MD5: 5e9dbfe2c2c5a7ada9666cb9fe59546b SHA-1: 46640b558782184abc31e30385e825e045928132 SHA-256: b4145c6f98c90165ba24fb6ededd0e8e1bdc0b1e74890239845ffa6648a419fb
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many of which appear to be compromised WordPress installations used for hosting malicious PDFs. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics suggests a link farm designed to distribute malware or phish users. No scripts were extracted, but the overall structure and URL patterns are indicative of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9915

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://crewmak.ru/uplcv?utm_term=addition+word+problems+for+class+4 PDF link annotation
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1609c2851358d6---67844930816.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092d2bef3554---pufiba.pdfIn PDF document text
    • http://www.studiolegalefusimorelli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608201951610e---pilesaxozam.pdfIn PDF document text
    • http://enjoy.sk/editor_uploads/system/files/64705691990.pdfIn PDF document text
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/q1qf5obs41tt2lpissvp39dfsh/62252825649.pdfIn PDF document text
    • https://frontlinetherapist.com/wp-content/plugins/super-forms/uploads/php/files/756d22c6cd92f2b14e37dcabc71edb47/60138036951.pdfIn PDF document text
    • http://www.jobsincrete.gr/images/_user_na/file/fakovunivujivij.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094840e8d2f3---kumawuzugozot.pdfIn PDF document text
    • http://phillipwhiting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cef46aab87d---80337381856.pdfIn PDF document text
    • http://accessprecision.com/userfiles/file/xanozew.pdfIn PDF document text
    • https://sieompaysdebray.fr/lesiom/txt/imgadmin/file/90410343923.pdfIn PDF document text
    • https://noble-worldwide.com/wp-content/plugins/super-forms/uploads/php/files/ae783ffa13651f475fc9c3faa4438c63/jopudukunepetenukemiz.pdfIn PDF document text
    • http://lasfyy.com/uploadfile/file/20210531190019548.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e2d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2D0 5400 bytes
SHA-256: 13df98f5453d766ec7691dc1a0d7fee27d436bc161da6dc9e10460b9723fc5f2
font_01_sfnt_off0000f517.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF517 11016 bytes
SHA-256: 22896814351200313f42c2c4f6819c8a30affdb58223a639b811a16f1139d4f1
font_02_sfnt_off00011a7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A7B 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176

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