Malicious PDF — malware analysis report

Static analysis result for SHA-256 dd491cb6b22db30e…

MALICIOUS

PDF

82.6 KB Created: 2021-04-20 12:17:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: a90e7ca422a269a7b633d090fbd25399 SHA-1: ca49d97169f0ffe8026724916b44c693ab277b80 SHA-256: dd491cb6b22db30e818ebce6758e602e218070a2219b73004d797f6291dc7f93
186 Risk Score

Malware Insights

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

This PDF file was identified as malicious by a ClamAV detection and an ML classifier. It contains a large number of external links, many pointing to disposable hosting, suggesting a link farm or SEO manipulation tactic. One of the primary URLs extracted is https://midufefew.ru/strik?utm_term=leisure+bay+spa+heater, which is likely part of the malicious infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

Heuristics 6

  • 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.
  • 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://midufefew.ru/strik?utm_term=leisure+bay+spa+heater PDF link annotation
    • http://lukorodipus.iblogger.org/articles_exercises_upper_intermediate.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420224/normal_5fd30aa8ea94f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4487894/normal_6047b9e1cf952.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366344/normal_601321d93b96f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478716/normal_605d8682263c3.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4448548/normal_5fcf07ebbdde3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369786/normal_606344835c37c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4376857/normal_606c812f4f4b7.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4503617/normal_5fc8dcc31ed58.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4374369/normal_6054ba0728b37.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4481841/normal_60016d133988a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4425924/normal_60295af3bcffd.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4410199/normal_5ff79d747fb12.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4419847/normal_602403dd1dcd0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4480895/normal_6062668509359.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://xipitidugizen.rf.gd/70512538354.pdfIn PDF document text
    • https://s3.amazonaws.com/paxunu/tamil_new_movies_2019_hd.pdfIn PDF document text
    • https://s3.amazonaws.com/xoferuzu/how_to_hook_up_dish_to_tv.pdfIn PDF document text
    • http://rupawozafope.epizy.com/vufidonolabexezetixibez.pdfIn PDF document text
    • https://b7e73dfe-ad35-4791-b4f7-7500f5b7882c.filesusr.com/ugd/bc79a4_5a9d54a5c0fb4cfc8542be6b0a78771d.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/gomaxod/agua_de_beber_jobim.pdfIn PDF document text
    • https://b5526579-b22d-45a0-8251-9885a72cf3eb.filesusr.com/ugd/0cd019_3400e8db95ad4cc2adf404859cdbf9e3.pdf?index=trueIn PDF document text
    • http://rodaselawowov.rf.gd/29933735998.pdfIn PDF document text
    • https://s3.amazonaws.com/kudowo/codepen_vue_template.pdfIn PDF document text
    • https://2ddc7431-ff91-46e9-9708-195efd6cc195.filesusr.com/ugd/ffe0d3_411b8e8713d34cfcac61d47280926db0.pdf?index=trueIn PDF document text
    • https://77a48bbd-706a-45f8-a225-ac1cc02029d7.filesusr.com/ugd/3be48b_d53bcb07329d40c591ab76c8da91bf5f.pdf?index=trueIn PDF document text
    • https://44034db3-6cdd-4729-adf3-7ccd6afcf354.filesusr.com/ugd/9fe9cc_709a7ea9ecf441a9ac39ae57fa93dfce.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/mozirolinitaje/balance_sheet_reconciliation_accounting_coach.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f963.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF963 4724 bytes
SHA-256: f89626888d88884d95ec876fbf5d41a749dd1648e1b891a11153adcec690617b
font_01_sfnt_off00010984.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10984 11000 bytes
SHA-256: 806815468dd7fdbbfeb4712060df941dff4263902ebc2a60129c31e1bb99f574
font_02_sfnt_off00012ed3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12ED3 4324 bytes
SHA-256: 4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3