Malicious PDF — malware analysis report

Static analysis result for SHA-256 15b998e99a7b9b48…

MALICIOUS

PDF

88.7 KB Created: 2021-06-01 09:11:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: fc936b9f8606397f629712197e253bea SHA-1: d1fce73ee3d0af4fbbf5ba8cb2dced63c0e09ee4 SHA-256: 15b998e99a7b9b488c784d5fe567283efa15e5979178153188a08f18ff258cd8
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to compromised WordPress upload storage, suggesting a phishing or malware distribution lure. The document body is heavily obfuscated, preventing a detailed analysis of its specific content, but the overall structure and URL targets are indicative of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160af9a15edef0---wamejagilegofuguso.pdf In PDF document text
    • https://www.icslights.com/wp-content/plugins/super-forms/uploads/php/files/3150b13d104a955b42fa5dfc7aecc02e/44662505080.pdfIn PDF document text
    • https://www.hdontheroadnapoli.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609c3e22a916e---48871985281.pdfIn PDF document text
    • http://boschvietnam.vn/files/usersfiles/files/43608935265.pdfIn PDF document text
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095244bd6f5a---77776297822.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16099e83568ddc---jujejuzazojugodoka.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/e663f27a62e584108d61ee09e92a7bbc/30076842372.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/q2ve0k57v6vqdk8didsgj5u0r1/73954598527.pdfIn PDF document text
    • https://performanceltg.com/wp-content/plugins/super-forms/uploads/php/files/c88e32d507c53973e4ed481a1caed9de/63134577605.pdfIn PDF document text
    • http://www.doctor-carpet.com/wp-content/plugins/super-forms/uploads/php/files/lncm15gs98uehe7j8r6dg7mnb3/zobigalusijubumowijekux.pdfIn PDF document text
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/42a6ee961bc2ddd958f23c0395260bd0/rosidelel.pdfIn PDF document text
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/16084078622ac0---78782950435.pdfIn PDF document text
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609bd1801a4c7---xokogafuwelesobumoramid.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160afc7a205e90---98757049959.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=kt76c+transponder+installation+manualPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000119ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119AB 5424 bytes
SHA-256: 71fe8ad8ff3730f1a9e612bab4cc1b6e5aab52ba628ab28d4e340b811a891718
font_01_sfnt_off00012c0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C0F 12440 bytes
SHA-256: 5f019cb9a486c8154fb617a5cddd6247207c6773dbf3e0193bfa4240ef0792c6