Malicious PDF — malware analysis report

Static analysis result for SHA-256 130b9e978835098f…

MALICIOUS

PDF

77.3 KB Created: 2021-06-05 07:26:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: baab87015e18f59fa36440351c31d6ad SHA-1: dc142475bbea6ba7bc6264084db7f53e4b13ca02 SHA-256: 130b9e978835098f542a619e9618d8eb51fbbb4e395f2dba64dcbc8c56543cc4
206 Risk Score

Malware Insights

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

The PDF contains a malformed exploit stream and a large number of external links, many pointing to disposable hosting, suggesting a link farm or SEO spam campaign. The embedded URL 'https://medvor.ru/pbw?utm_term=what+is+fertility+rate' further supports the lure of a search result. While no scripts were explicitly extracted, the PDF structure and heuristic firings indicate malicious intent, likely to redirect users to malicious or spam content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • 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.
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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://medvor.ru/pbw?utm_term=what+is+fertility+rate PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4365606/normal_60484a045723d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4447079/normal_601809bd2899b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366305/normal_601a8e25c37c0.pdfIn PDF document text
    • https://jiburivaduvu.weebly.com/uploads/1/3/4/4/134473865/655e555bf28ea.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366385/normal_6049ed3de7702.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4389821/normal_6068f4af43b33.pdfIn PDF document text
    • https://nirilixurem.weebly.com/uploads/1/3/4/4/134474770/sekitasuri.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367665/normal_601d0522687d0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454984/normal_6033ea286dada.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366029/normal_60223fdb44e17.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490129/normal_60635346aa950.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/4d9cbf9a-b495-4806-a119-8403ffa3a039/sifosamogiporujorurere.pdfIn PDF document text
    • http://pupowivala.pbworks.com/w/file/fetch/144425874/defawafapovukakuzolunulup.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e935ad38-8bb4-4ecf-aca1-65ee82f0e2bf/what_are_descriptive_words_in_poetry_called.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/09a8158e-a199-4062-be57-873cb370c0ea/82580957857.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/76addcaa-7637-413a-9e4d-a44ab4d13fda/kezirufetor.pdfIn PDF document text
    • http://zejokij.pbworks.com/w/file/fetch/144631050/ben_10_alien_force_psp_codes.pdfIn PDF document text
    • http://bukafag.pbworks.com/f/how_is_jail_time_calculated_uk.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/00d3f20f-e74a-4d83-a1fc-fcd3c3da74b1/does_fios_have_redzone.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1272d048-07cb-4cbb-8898-065f483b04b3/irobot_braava_jet_m6_microfiber_pads.pdfIn PDF document text
    • http://vejivab.pbworks.com/w/file/fetch/144558339/xirezujokag.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_off0000f2f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2F8 4968 bytes
SHA-256: de1946c3e931f524125baa3f7e746e0e317e6839810c5e1685a9dfd12ec98776
font_01_sfnt_off000103ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103ED 10532 bytes
SHA-256: c2cb052c304acd691efacf768a5a259b43aff9022b782e4271331ea2fb842854