Malicious PDF — malware analysis report

Static analysis result for SHA-256 162098acc71f9ee0…

MALICIOUS

PDF

69.8 KB Created: 2021-09-27 01:35:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c5f8436600a1370a8ebc3dcc25964f8b SHA-1: ce736a64825e612065b37b0fb23f6185f390cc93 SHA-256: 162098acc71f9ee00c6bf67dbc5bd466647e9794575396b8af0169fad99c6210
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of links, many pointing to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery through these external links. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://krisoc.ru/uplcv?utm_term=abnormal+upper+esophageal+sphincter+function PDF link annotation
    • https://mmtours.si/uploads/gabaturufosawoka.pdfIn PDF document text
    • http://host.keraladreamhomes.com/~viswabrahmathach/admin/fckeditor/editor/filemanager/connectors/php/userfiles/file/31310216732.pdfIn PDF document text
    • https://macjiboter.macjahisa.si/files/file/97809076688.pdfIn PDF document text
    • http://sgrdinstitutionspandher.org/sgrd/userfiles/file/29142970179.pdfIn PDF document text
    • http://ne-moloko.ee/wp-content/plugins/super-forms/uploads/php/files/c5117bc2aebe66c8755292db8da23ab3/wezekafokoletitatekemu.pdfIn PDF document text
    • http://bodegaadrover.com/userfiles/imagenes/82778911902.pdfIn PDF document text
    • https://hbphoto.ca/resimler/files/lezotalorakupulafawu.pdfIn PDF document text
    • https://rougezenekar.hu/files/file/sixigitepodoronosaz.pdfIn PDF document text
    • http://jcbcharpentebois.com/ressource/site-image/files/pinexodamivilub.pdfIn PDF document text
    • http://richardchong.com/userfiles/files/29964193330.pdfIn PDF document text
    • http://emilygrilltogo.com/uploads/files/60068216681.pdfIn PDF document text
    • https://www.albispanaderia.com/wp-content/plugins/super-forms/uploads/php/files/fdfdad629a570a41524e1c803f8afe60/20314321020.pdfIn PDF document text
    • http://hrzservices.com/uploadfiles/file/65585450281.pdfIn PDF document text
    • http://status-go.net/gfx/userfiles/files/57492805949.pdfIn PDF document text
    • http://studiodelcorso.eu/userfiles/files/rijedulodunatazefun.pdfIn PDF document text
    • https://geneticapanama.com/userfiles/file/lovuwalopasatibatigabi.pdfIn PDF document text
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613488b019ed7---5219709024.pdfIn PDF document text
    • http://ume.civilkozpont.hu/uploads/file/40615125253.pdfIn PDF document text
    • http://ajk-opakowania.eu/upload/fck/file/finigoxaw.pdfIn PDF document text
    • https://bnbtravels.com/ckfinder/userfiles/files/8777457049.pdfIn PDF document text
    • https://ardiinerkh.mn/uploads/userfiles/files/85010672300.pdfIn PDF document text
    • http://tccsrl.org/userfiles/files/koniviriro.pdfIn PDF document text
    • http://lblussana.it/images/file/betemenojujeveweliviwapat.pdfIn 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://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_off0000af0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF0A 11148 bytes
SHA-256: f0d077275647d7c3036037efea2dc621cfd3ea984261ed52601a95e8fae3419b
font_01_sfnt_off0000c8af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8AF 16252 bytes
SHA-256: f09c1b047e99bda3e445271bf0d8a327c1b3ff0ca0523310fa1d2ff92473728a
font_02_sfnt_off0000f16c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF16C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1