Malicious PDF — malware analysis report

Static analysis result for SHA-256 3ab95c675ae9256d…

MALICIOUS

PDF

77.1 KB Created: 2021-03-22 16:18:48 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: b249b54cb0eefde51499bb556b8ad9d7 SHA-1: cef403044d61148e5af71102192887d79220470d SHA-256: 3ab95c675ae9256ddf5d9a9e302f7f370ec0d3904ffc225c2977f61fc541bcd6
186 Risk Score

Malware Insights

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

The sample is a PDF document that contains a large number of external links, characteristic of a link farm designed to distribute traffic or host malicious content. One of the extracted URLs, https://pelibifir.ru/strik?utm_term=dell+t7500+specs, is flagged as malicious. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 6

  • 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.
  • 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 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://pelibifir.ru/strik?utm_term=dell+t7500+specs
    • https://cdn-cms.f-static.net/uploads/4366957/normal_60330b7c2a78d.pdf
    • http://repair-monokoles.ru/kubigexililelenevmsqqj.pdf
    • https://dekajemo.weebly.com/uploads/1/3/1/4/131453049/6756690.pdf
    • http://yarrebitteh.online/1._mouawad_1001_nights_diamond_purseb0xkj.pdf
    • https://gigadejelurare.weebly.com/uploads/1/3/0/8/130874533/45cc13c1c86.pdf
    • https://jasugupaxawuz.weebly.com/uploads/1/3/0/7/130740610/luwavajapizev.pdf
    • https://cdn-cms.f-static.net/uploads/4421776/normal_601de875e8095.pdf
    • https://cdn-cms.f-static.net/uploads/4452385/normal_6056e816bbc94.pdf
    • https://static.s123-cdn-static.com/uploads/4496402/normal_5ff997458cc04.pdf
    • https://zupawifotifawe.weebly.com/uploads/1/3/4/4/134480263/cd9726f3.pdf
    • http://de-bewertung-id-q2e5t23.top/baby_cakes_instruction_manuall7f8y.pdf
    • http://pinerapidsrr.com/52622881204tff9a.pdf
    • https://gujowidupisume.weebly.com/uploads/1/3/4/1/134131448/xetotujuviwu-bobig-dixajirikij-zisinezebunat.pdf
    • https://cdn-cms.f-static.net/uploads/4476281/normal_600dbf8921717.pdf
    • https://getenulezawo.weebly.com/uploads/1/3/4/8/134897364/sopewago-tijarug.pdf
    • https://wigadanoj.weebly.com/uploads/1/3/4/4/134404864/sedujelopexovu.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cc968bdf-8a18-4a65-a72d-893c706ef441.filesusr.com/ugd/bae363_f2996e334ec74af28bdf6bbfd6b9bfaf.pdf?index=true
    • https://f64a1a0a-debf-4843-a838-a34c0cae0f4a.filesusr.com/ugd/89602e_79560e260f4045a890fb2bad4fa97124.pdf?index=true
    • https://uploads.strikinglycdn.com/files/1d3ba761-1856-4e03-86e9-ee6af96e80c9/principles_of_engineering_economic_analysis.pdf
    • https://d525ee04-2a40-494f-8ba9-fee52f7b18ee.filesusr.com/ugd/8b8e24_9c531a6b153b49b187e170efe858a11e.pdf?index=true
    • https://ff4d9611-e7ea-45f2-85d3-f0b464ef817f.filesusr.com/ugd/48f461_e0bb04086db94fe2a063a69339469eef.pdf?index=true
    • https://uploads.strikinglycdn.com/files/8afd3624-77ea-4f4b-9a98-a548a0955d53/norcold_n611rt_thermistor.pdf
    • https://uploads.strikinglycdn.com/files/dbeb3c92-3da4-4d9e-88a0-08e6014f980a/what_is_the_weather_for_salem_oregon.pdf
    • https://e6c529cc-411f-4195-b5ea-7b5fd081490a.filesusr.com/ugd/b7ab08_7c40971150c74154a4736a87bd500c47.pdf?index=true
    • https://uploads.strikinglycdn.com/files/93163405-4503-497d-b2cf-24513ff3878e/thermador_gas_stove_owners_manual.pdf
    • https://uploads.strikinglycdn.com/files/7380307f-85e3-442c-adae-831f300b0f27/xigatorifitizezazur.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f1aa.bin
eba9b408c34f50040ee65bdd34ca3fd46a39f24e0febd1a950b2c953d9c12deb
pdf-font-stream PDF embedded font (sfnt) at offset 0xF1AA 4964 bytes
font_01_sfnt_off000102bc.bin
8888d345c30c8e86e4f6a6816f47b6667f8a661907e1a6b812a7a4ac532f2294
pdf-font-stream PDF embedded font (sfnt) at offset 0x102BC 10604 bytes