Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c43f7d3da7a9d21…

MALICIOUS

PDF

88.2 KB Created: 2021-07-28 01:05:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 609a32ab7b9965cb8164a3e8396d0489 SHA-1: 0f78ce5c04b3d60a7e0bb24dcc7a12f19cb18272 SHA-256: 8c43f7d3da7a9d21f171f34975b29e52002d99a8625d3732b234833c36a7379e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous links pointing to compromised WordPress upload storage and other disposable hosting, suggesting a link farm designed to distribute malicious content. The document body is heavily obfuscated, but the presence of external URIs and link farms points to a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f117194d30---laxixuvowopejesutenapetux.pdf In PDF document text
    • https://narimasu-chintai.net/jcfiles/file/67579450435.pdfIn PDF document text
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/aa4dbf8fe28f73a706f1a737f7f9d561/33812789342.pdfIn PDF document text
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/q99mbl419rno3sr72d89ihubvn/52541077652.pdfIn PDF document text
    • https://big-affaires.com/img/pics/files/nizefanusegosefe.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160e62485ed8bc---gujawo.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a78c84b50d---2473879631.pdfIn PDF document text
    • http://short-story.ru/upload/file/munasumosifunazujagu.pdfIn PDF document text
    • https://bhiringisamsankalimandir.org/ckfinder/userfiles/files/88250935854.pdfIn PDF document text
    • https://akapacha.com/userfiles/file/61326109161.pdfIn PDF document text
    • http://ranjitabiswas.com/userfiles/files/44447157262.pdfIn PDF document text
    • http://www.aqsclimited.com/EditorImages/file/19574322147.pdfIn PDF document text
    • http://choinka4x4.org/cms/files/file/tomuwurugefali.pdfIn PDF document text
    • https://castel.ro/userfiles/file/76871016358.pdfIn PDF document text
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d698a628c4---8859571586.pdfIn PDF document text
    • https://refour.eu/wp-content/plugins/super-forms/uploads/php/files/2dc8435222843641e8d4ab7d93c2e935/kasedavazurimivigugar.pdfIn PDF document text
    • https://aspaeng.com/files/image/files/94661072794.pdfIn PDF document text
    • https://ltgtrends.com/wp-content/plugins/super-forms/uploads/php/files/d074bf0b290918e20ffe10489883a114/83581560626.pdfIn PDF document text
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160f06f8176c18---xiwewoxal.pdfIn PDF document text
    • https://acornschoolcharleston.org/wp-content/plugins/super-forms/uploads/php/files/de2d09480541f8f07b1b8d02727b2b9c/sekenirebiluvonowunur.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a0ec6007d6---3353482022.pdfIn PDF document text
    • http://c-amc.com/upload/files/tokezezobomelujeginajizex.pdfIn PDF document text
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/8022941a1ebb82b5d53c04124899ba1d/27892852411.pdfIn PDF document text
    • https://stpeterscbs.ca/ckfinder/userfiles/files/fisuwo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=schedule+3+balance+sheet+format+pdf+downloadPDF 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_off0000f302.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF302 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010b14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B14 16900 bytes
SHA-256: 56ab4a5aefda4f6092f19817beafe99bb6b0b018aa86b0186549a5b44fe3db5e
font_02_sfnt_off00013754.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13754 11364 bytes
SHA-256: d1b28cd5e9b1e99007727d831f1e1540349254e02bc77b10deb48d7349db6069