Malicious PDF — malware analysis report

Static analysis result for SHA-256 661cc0c4685eacca…

MALICIOUS

PDF

78.6 KB Created: 2021-06-05 09:48:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-04
MD5: 34003f2947f2ca17cccf4b91954f8fb1 SHA-1: 512af9614c5449e7f3206d955e397cad5da4fc13 SHA-256: 661cc0c4685eacca95df73583d43485e60d67a9659482a139d277ef305e13168
226 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a security-bypass lure. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • Security software disable instruction high SE_SECURITY_BYPASS
    Document instructs the user to disable antivirus or security software — unusual for ordinary documents and high-risk in an unsolicited file
  • 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://infrive.ru/pbw?utm_term=why+is+my+xfinity+modem+blinking+yellow PDF link annotation
    • https://lakiregatu.weebly.com/uploads/1/3/4/5/134589313/1529089.pdfIn PDF document text
    • https://pugufewosanagut.weebly.com/uploads/1/3/4/3/134331363/fd6a6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481990/normal_603f422a150a3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4423715/normal_5fe61b3c80675.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4501229/normal_6008dd59da6df.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4388614/normal_60b9aebf30700.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/2649ebf5-1c00-423e-9001-1051547fbd89/multivariate_statistics_in_research_methodology.pdfIn PDF document text
    • http://fuzujufod.pbworks.com/f/gojogixigeguf.pdfIn PDF document text
    • http://xiwitanul.pbworks.com/w/file/fetch/144458277/nuwazebosed.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c3ed5a92-0207-4ab2-a59a-eeda171bcbeb/64112027897.pdfIn PDF document text
    • http://nerobedevu.pbworks.com/w/file/fetch/144570741/62460746362.pdfIn PDF document text
    • http://figuduvimeti.pbworks.com/w/file/fetch/144514929/jebuzisasunipuzuz.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7cb2065a-3e60-4e51-93f5-c74f15199d77/lerubuw.pdfIn PDF document text
    • http://xutosop.pbworks.com/f/matousek_-_invitation_to_discrete_mathematics_solutions.pdfIn PDF document text
    • http://letonepamusi.pbworks.com/w/file/fetch/144440142/65612684361.pdfIn PDF document text
    • http://sovafiben.pbworks.com/w/file/fetch/144539601/elsgolts_l._differential_equations_and_calculus_of_variations.pdfIn PDF document text
    • http://wepadigisita.pbworks.com/w/file/fetch/144630741/42880432770.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/aa471ccd-3659-4e4c-80ed-06d16807e5f3/xevelozamiru.pdfIn PDF document text
    • http://sofutikajen.pbworks.com/w/file/fetch/144455796/refillable_ink_cartridges_for_epson_artisan_1430.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/223c6635-e313-49bb-9ba5-e2a044e922df/is_manhattan_prep_gre_accurate.pdfIn PDF document text
    • http://bunemirudezo.pbworks.com/f/ejercicios_formulacion_inorganica_3_eso_iupac_2005.pdfIn PDF document text
    • http://gulisapil.pbworks.com/f/teritozolopevalaki.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f4d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4D4 5496 bytes
SHA-256: ef5c64c214500bfe5cc31b745f247a50038d5081c5d046ce89a545c39193aa06
font_01_sfnt_off00010789.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10789 11004 bytes
SHA-256: 88546ed9785a850ed1e345a82393db0431ce505c879cedc51d0a07c2d69a6ac1