Malicious PDF — malware analysis report

Static analysis result for SHA-256 16cd5c1caf07c0f3…

MALICIOUS

PDF

84.8 KB Created: 2021-05-25 09:28:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-31
MD5: aaaa1887de2ab67741d7714d5dbc53c1 SHA-1: b7cf2f356ef8764f5f41ae9d40aa397e3dd943a8 SHA-256: 16cd5c1caf07c0f34c010e0ae641041537ae32b8df4d43ba8ca9240e20911294
164 Risk Score

Malware Insights

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

This PDF was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier with high confidence. It contains numerous links to compromised WordPress sites, suggesting it is part of a link farm designed to host and distribute malicious files. The presence of a 'download button' heuristic further supports the intent to trick users into downloading a payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://shayangroup.net/wp-content/plugins/super-forms/uploads/php/files/3324ba7ca193af24c4235c1391530e2f/4515359516.pdf In PDF document text
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/297064cbfbfa00a07673b74c4750b18a/59448865793.pdfIn PDF document text
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160871d7e6619b---ludetemolusudojorelegug.pdfIn PDF document text
    • https://robertmatzuzi-massagetherapist.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160717776a7c70---80943840121.pdfIn PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16088d5b79e69d---tulop.pdfIn PDF document text
    • https://thesaddlebank.com/wp-content/plugins/super-forms/uploads/php/files/8pavivgd8hl2231d8t1u7s6v5h/7924097284.pdfIn PDF document text
    • http://learningkey.org/userfiles/saxono.pdfIn PDF document text
    • https://www.alarisusallc.com/wp-content/plugins/super-forms/uploads/php/files/de2536fd5ff3a01a61530fd1f62bbccb/rogopoj.pdfIn PDF document text
    • https://ceccarbotosani.ro/userfiles/file/42893958868.pdfIn PDF document text
    • http://www.asslar.de/downloads/61280505827.pdfIn PDF document text
    • http://traiteur-ribot.fr/userfiles/file/vomununigagaxefoko.pdfIn PDF document text
    • https://www.pharmaright.ca/wp-content/plugins/super-forms/uploads/php/files/i78853k88natrnodigm43eu2sb/kujavimij.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606e8539b421a---ririjiwanajopetebolepopuf.pdfIn PDF document text
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072efe148073---pamilomupaben.pdfIn PDF document text
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16093862b12251---84055772670.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/BkSY9tpko7c/uplcv?utm_term=why+is+the+red+light+flashing+on+my+indesit+dishwasherPDF 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_off00010b8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B8A 5528 bytes
SHA-256: 162d16364674850912a21d9fd1b6136091d40e65837422d5e45be5301f6dde1f
font_01_sfnt_off00011e4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E4E 11784 bytes
SHA-256: d46151d484a3f0d96673d3e1c413d307b3857417d49f6c675919d38b82c57c51