Malicious PDF — malware analysis report

Static analysis result for SHA-256 88ff1eb33243abe1…

MALICIOUS

PDF

77.0 KB Created: 2021-03-05 06:51:23 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 3b59e5c40e9c5ff3ea8f027bac56a4fc SHA-1: 11a924aa876281eacc36ccce9a15e0d5039ad871 SHA-256: 88ff1eb33243abe1ffdcc940adb1727b878194a7bdf3b2977e8439f5cb7aa9a9
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://leonvi.ru/strik?utm_term=what+fruits+to+eat+for+gerd PDF link annotation
    • https://siromalad.weebly.com/uploads/1/3/5/3/135312661/1113291.pdfIn PDF document text
    • https://lareduna.weebly.com/uploads/1/3/1/4/131453109/zeraku_tonoguxu.pdfIn PDF document text
    • http://marinarus.space/gojibuwonirugepidubitoiri60.pdfIn PDF document text
    • https://sufotope.weebly.com/uploads/1/3/0/7/130775917/lelajuseb.pdfIn PDF document text
    • https://tajurasexir.weebly.com/uploads/1/3/1/6/131606020/5224210.pdfIn PDF document text
    • https://janirakuvofubej.weebly.com/uploads/1/3/4/7/134734148/e61a9c929a7afb.pdfIn PDF document text
    • http://lighterusb24.site/samsung_top_loader_washing_machine_user_manualukpus.pdfIn PDF document text
    • https://jipukikibowema.weebly.com/uploads/1/3/4/6/134633032/mujigexiwumozu.pdfIn PDF document text
    • http://heliusdesign.ru/8849420112085gzk.pdfIn PDF document text
    • https://buronoveze.weebly.com/uploads/1/3/0/7/130739674/kunijemuweku.pdfIn PDF document text
    • http://gk-kuban.ru/vusujezedidanekerazagm78dr.pdfIn PDF document text
    • https://kijomexed.weebly.com/uploads/1/3/1/0/131069838/givog-zanalunumot-fosemi-zebivotiveka.pdfIn PDF document text
    • https://fufejaxogepevi.weebly.com/uploads/1/3/4/4/134485438/komotiwad.pdfIn PDF document text
    • http://maykistore.ru/buxany94fy.pdfIn PDF document text
    • http://info-pages.ru/senior_data_analyst_skill_setj6kjq.pdfIn PDF document text
    • http://voyazh-shina.com/what_are_the_principles_of_effective_teaching_and_learninglaorb.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/tikoweravisixu/jejusuzuzovo.pdfIn PDF document text
    • https://s3.amazonaws.com/loxopudizus/ca_regular_withholding_allowances_worksheet_a.pdfIn PDF document text
    • https://ca39a19f-16f9-469f-ab0b-65ec0463b8d0.filesusr.com/ugd/cc9b97_af2b155b25e8494f831a832da69035b6.pdf?index=trueIn PDF document text
    • https://6f4861c6-cdf0-4a5f-ba2d-f9c5e5bfbee6.filesusr.com/ugd/77941b_ffc0c38b3e31484d97137c69016d8e67.pdf?index=trueIn PDF document text
    • https://7fd92c66-d3af-485c-b7a9-31529ddfb1b5.filesusr.com/ugd/997d0f_15d77a633d0c4459908883fde44eac04.pdf?index=trueIn PDF document text
    • https://1c8fadd7-09eb-4d2b-9d42-8e747ba5ce52.filesusr.com/ugd/60625b_350c554d980c4553871ed10985ae7149.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/piwupevivotixi/causeries_1948.pdfIn PDF document text
    • https://s3.amazonaws.com/babetafaperaxov/30263761545.pdfIn PDF document text
    • https://s3.amazonaws.com/bidurudilidujug/67488999500.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_off0000ef59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF59 5148 bytes
SHA-256: 30b055a51a85260a856bf09056e73870695a0c93c902214e21011cf16c591187
font_01_sfnt_off000100e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100E8 11308 bytes
SHA-256: 171a660dd149512dfdda524282858f305d9d180198957f69b0e7ba0b1d7a060d