Malicious PDF — malware analysis report

Static analysis result for SHA-256 9d85fb5076ff83b2…

MALICIOUS

PDF

75.7 KB Created: 2021-06-08 06:16:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: a35fb8183798c5655e514a4acd36d5d6 SHA-1: 15d970a654fc416bbf7a117eec1cc90c534a0d7c SHA-256: 9d85fb5076ff83b221494c5b5b23cb960fa07280c90d36365b74ce4acd30458b
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a significant number of external links pointing to disposable hosting services, identified as a link farm. The primary URL, 'https://krisoc.ru/pbw?utm_term=fundamentals+of+human+anatomy+and+physiology+pdf', is presented as a lure. The heuristic 'PDF_SEO_LINK_FARM' indicates a mass of external PDF links, suggesting a coordinated effort to distribute content or phish users. ClamAV also detected this file as 'Pdf.Phishing.Trojan'.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://krisoc.ru/pbw?utm_term=fundamentals+of+human+anatomy+and+physiology+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4471686/normal_6018631ee2f35.pdfIn PDF document text
    • https://bukojawuwo.weebly.com/uploads/1/3/4/5/134508808/8c134f4525.pdfIn PDF document text
    • https://rifusefabizavi.weebly.com/uploads/1/3/2/3/132303317/55fd52b42bd71a.pdfIn PDF document text
    • https://fojexoduzasob.weebly.com/uploads/1/3/4/6/134693365/desetalim_faradodumi_relagote.pdfIn PDF document text
    • https://xodetawutal.weebly.com/uploads/1/3/0/7/130774968/9242516.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4478393/normal_60010c4ad6b1f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4410016/normal_60247fbf8d751.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4418199/normal_601d5143dc409.pdfIn PDF document text
    • https://negopipeminote.weebly.com/uploads/1/3/4/8/134885603/c9a0b000dac.pdfIn PDF document text
    • https://funovupudejo.weebly.com/uploads/1/3/4/4/134473131/dazofe.pdfIn PDF document text
    • https://talonira.weebly.com/uploads/1/3/4/8/134895983/38fdf0d98.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4402261/normal_60b561327016a.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4419630/normal_60b723253eb05.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481828/normal_5fe66bfa6917b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366359/normal_600d3f8c38d01.pdfIn PDF document text
    • https://jafowunasakubiv.weebly.com/uploads/1/3/1/4/131437393/928092.pdfIn PDF document text
    • https://savigopomela.weebly.com/uploads/1/3/4/8/134886046/nudidupedajilu-lewopikijaxabop-nufanefagu.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4450259/normal_5ff39bff50881.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4369506/normal_5fc67cd1260b0.pdfIn PDF document text
    • https://zisawotagaxikad.weebly.com/uploads/1/3/4/4/134478332/wiwabojez-biretejebu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://natofuke.pbworks.com/w/file/fetch/144780267/how_do_you_write_a_discharge_summary.pdfIn PDF document text
    • http://najajadux.pbworks.com/f/2183121292.pdfIn PDF document text
    • http://joxakuruvi.pbworks.com/w/file/fetch/144831141/how_do_i_cook_steak_on_a_george_foreman_grill.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_off0000ebcd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBCD 5416 bytes
SHA-256: 88d9065a5bf7911b8652f18460548c4a163801b1efd2408ce5bf0657ed627c5e
font_01_sfnt_off0000fe29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE29 10332 bytes
SHA-256: 3689fecc3ca6666b94b943ce02d81044d04c71bdadb7bbb672a999d15755a0c7