Malicious PDF — malware analysis report

Static analysis result for SHA-256 13819ff4d707f669…

MALICIOUS

PDF

74.0 KB Created: 2021-06-04 01:41:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 9fb42e191b29e606864e6f8324415573 SHA-1: 2667b28abc726a3d84879ab4846bd9be827f4307 SHA-256: 13819ff4d707f66976e361e4c5097619ecec681db7891101d0191d01cd10d66c
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a phishing or trojan payload. It contains a large number of external links, many hosted on disposable domains, suggesting a link farm designed to redirect users to malicious content. The primary URL identified is 'https://medvor.ru/pbw?utm_term=libro+semillas+estelares+pdf', which likely serves as a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • 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.
  • 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=libro+semillas+estelares+pdf PDF link annotation
    • https://tanezogifa.weebly.com/uploads/1/3/4/3/134321065/f58cc374.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4465149/normal_6002a700b3c0d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4405662/normal_5fe84149801df.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4419857/normal_603f5bb866c3e.pdfIn PDF document text
    • https://mibelovo.weebly.com/uploads/1/3/4/6/134608705/legarizete.pdfIn PDF document text
    • https://terekutididir.weebly.com/uploads/1/3/0/9/130969195/ralujemesizufa.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459787/normal_602eb287b0e29.pdfIn PDF document text
    • https://gikijeza.weebly.com/uploads/1/3/4/4/134465371/6c4dc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4412899/normal_5fd5f08890c36.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4404987/normal_603d2c6570bad.pdfIn PDF document text
    • https://nabinavupofi.weebly.com/uploads/1/3/5/3/135350319/262072.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4407318/normal_606b7761c00fe.pdfIn PDF document text
    • https://kisuvali.weebly.com/uploads/1/3/1/1/131163683/78da01ef.pdfIn PDF document text
    • https://bijimeko.weebly.com/uploads/1/3/4/3/134327756/netupegesov.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4418587/normal_5fdd680fe188b.pdfIn PDF document text
    • https://guxovegetixewaz.weebly.com/uploads/1/3/2/3/132302910/9067455.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470688/normal_60675fc7ab2d9.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/68949f83-5a31-45eb-bfb5-5bb82f70512a/ninajerunugibibaxid.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5bbb1e7c-40e0-45df-9ff9-37fe483d1d53/vapeduralaxawefadalidusuz.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/81a00594-7621-4f5f-b791-eb990adbfac5/gift_of_the_magi_summary_sparknotes.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_off0000df80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF80 5268 bytes
SHA-256: 47fd6703c7a98d41d08da7df2b5d21f98099489769181f4991a7f9af4b55f7b8
font_01_sfnt_off0000f14c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF14C 12384 bytes
SHA-256: ea986ebd87e9caa3839c83ca16da886655db158029ffa423a64959c277f0b385