Malicious PDF — malware analysis report

Static analysis result for SHA-256 8fcd16fe9d5c7837…

MALICIOUS

PDF

84.4 KB Created: 2021-06-10 15:48:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: d23b9f8fdef83f333034f6e1eb4b860b SHA-1: 4ff912ecff6dda95dfb0ba342464608c6cdf648d SHA-256: 8fcd16fe9d5c78371225a171215d1949617cb5a1eab587de84a2544ba5d3568c
156 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://pistant.ru/uplcv?utm_term=asphalt+8+not+downloading+data PDF link annotation
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a8544382e2d---sesavabebuvufu.pdfIn PDF document text
    • http://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/167fbd03d2ef8234ff422993d258bc59/25473949418.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/xuleledu.pdfIn PDF document text
    • https://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/01305c5f8cebbdfefc25d00e25fc400a/49055482667.pdfIn PDF document text
    • https://prosegik.com/wp-content/plugins/super-forms/uploads/php/files/6565f756767adb8bc2e1ee413d5be3cf/20383817000.pdfIn PDF document text
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/a5f15948826b73ae2438bcaf77356593/jamiwaf.pdfIn PDF document text
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca9c3c5827---79107910382.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/160b1c93ec0e4e---zazaganepug.pdfIn PDF document text
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ac47cce127---28194182933.pdfIn PDF document text
    • https://divinenine.net/userfiles/file/53958286424.pdfIn PDF document text
    • http://www.mkkdigital.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1607d14ce78439---11500455874.pdfIn PDF document text
    • http://envigest.cz/upload/file/44841390404.pdfIn PDF document text
    • http://hasyo.net/files/file/77711037205.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001006f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1006F 3112 bytes
SHA-256: 351e3391a290d65365ee023877a8535a2df0050cb126d5a876b41dddb64e8be8
font_01_sfnt_off00010bab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BAB 5400 bytes
SHA-256: d572002b84820dc944c09c0b418afaf20078d96ce07fb633a4dcddf189a1c18a
font_02_sfnt_off00011e1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E1B 11708 bytes
SHA-256: af6761b33d1b05b2dfa17dd37730081904578604e391c5ab6fefdf6ecd909eaa