Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5db8f98d3af7e6c…

MALICIOUS

PDF

73.1 KB Created: 2021-09-06 00:22:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b26f11ab42ebd5606bac23a1752527b6 SHA-1: 6796910b6e14ec2892f621f2441d629e98543d57 SHA-256: c5db8f98d3af7e6cff9e5a53abb4c2dba0ae07ee4f16292da28c773bfa91205d
156 Risk Score

Malware Insights

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

This PDF was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. The file contains numerous links pointing to compromised websites and disposable hosting, suggesting it's part of a link farm designed to redirect users to malicious content. The presence of external URI heuristics further supports the attack pattern of directing users to external, potentially compromised, resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://chieucoingason.vn/files/rikibowi.pdf In PDF document text
    • https://air-separation-supplier.com/d/files/vokegedop.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/160735caa35edb---94177423763.pdfIn PDF document text
    • https://glowskincare.net/wp-content/plugins/super-forms/uploads/php/files/78fbef62cd0e81c7b61ecb9c8fc6b28c/99057383983.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/c50e491253ca3da4bb6733072661244d/rejukebugoma.pdfIn PDF document text
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160971475c4304---11333428822.pdfIn PDF document text
    • http://twozonechickenlasvegas.com/uploads/files/31581357502.pdfIn PDF document text
    • https://alasclub.gr/neuro/ckfinder/userfiles/files/84725334659.pdfIn PDF document text
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4dfee22b77---jenorogusuja.pdfIn PDF document text
    • https://la-klamm.org/userfiles/file/nuseke.pdfIn PDF document text
    • http://greenworx.eu/images/uploads/files/31043523316.pdfIn PDF document text
    • http://esipro.fr/userfiles/file/98428499287.pdfIn PDF document text
    • https://chp-travel.ir/data/file/14387592493.pdfIn PDF document text
    • https://luathoanghuy.com/uploads/files/xazatabuzelovixutibe.pdfIn PDF document text
    • http://status-go.net/gfx/userfiles/files/76730930450.pdfIn PDF document text
    • http://elonsummerstorage.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1785edde01---78982807252.pdfIn PDF document text
    • https://stef-nancy.fr/upload/document/sogevezasivebebasafi.pdfIn PDF document text
    • https://mzlpro.com/web/img/podborky/files/nefarizozavupax.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d516768cd9---4332639975.pdfIn PDF document text
    • http://kystop.com/wp-content/plugins/super-forms/uploads/php/files/plmg5njf9uonmamdfr8aekj0f6/nuxokova.pdfIn PDF document text
    • https://dolmalatrek.com/userfiles/file/bigapiwenetipukop.pdfIn PDF document text
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082d4de7626f---bivexebawokeboxi.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/2ffbfa394d0eb1efa09be86494ffc67a/giputejimezazokimivado.pdfIn PDF document text
    • http://sualpturizm.com/userfiles/file/76721742521.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=icao+doc+8973+pdfPDF 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_off0000baf5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBAF5 17084 bytes
SHA-256: 6e5a3f2888cb394a69394f731b5b754c1ebbfd95e6e5480fffd0dc3d8086e535
font_01_sfnt_off0000e796.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE796 10420 bytes
SHA-256: 6f48087d0d7e1ccef64a2d0fba6a0831a488ea21d1eab9d71b31e519c845c350
font_02_sfnt_off0000ff67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF67 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1