Malicious PDF — malware analysis report

Static analysis result for SHA-256 831b78cb3efa483d…

MALICIOUS

PDF

44.5 KB Created: 2020-10-29 07:43:04 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: 8687325f93bb41689b1141d3ffc28e7a SHA-1: 381f5927d5587b7aef8f0a32661d55b163e21368 SHA-256: 831b78cb3efa483dad3c12400d2f23251a5af74fc6a390c8ef320f0dff95960c
154 Risk Score
Tags
free-cdn-ebook-manual-lure

Malware Insights

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

The PDF document contains numerous embedded links, identified as a link farm, directing users to potentially malicious websites. One prominent URL, 'https://ggtraff.ru/strik?keyword=sample+transmittal+letter+for+documents+submission', is flagged as a malicious redirector. The document's content is disguised as a transmittal letter, likely to trick users into clicking the malicious links, which is consistent with a spearphishing attachment attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://ggtraff.ru/strik?keyword=sample+transmittal+letter+for+documents+submission In PDF document text
    • https://fijefozumomaba.weebly.com/uploads/1/3/4/4/134491855/3b794.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369512/normal_5f8ce13da4a01.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368770/normal_5f8ec0906d572.pdfIn PDF document text
    • https://xedexebil.weebly.com/uploads/1/3/4/2/134235570/zazovatani-wuwivibuki.pdfIn PDF document text
    • https://viwuwobigoku.weebly.com/uploads/1/3/1/3/131378942/584ff28d2b5cfae.pdfIn PDF document text
    • https://fawefugixizim.weebly.com/uploads/1/3/1/3/131383791/cb033a194.pdfIn PDF document text
    • https://damijuvik.weebly.com/uploads/1/3/1/3/131381376/jopititamazisag.pdfIn PDF document text
    • https://rudofodirofebas.weebly.com/uploads/1/3/0/7/130739781/3228609.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366654/normal_5f8b57d278a01.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4377377/normal_5f94ebbde1e2e.pdfIn PDF document text
    • https://bizavurodetilu.weebly.com/uploads/1/3/4/3/134391156/c10b2c1.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
    • https://cdn.shopify.com/s/files/1/0501/7452/5594/files/94512966938.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0437/5651/9585/files/zezigupademes.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0439/4916/2654/files/pizakuzesivunogifepede.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b67a3770-7566-4c01-8d19-bff1579b7f17/20206715482.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e01f46f7-8057-494b-8cd3-d99089cef177/26989178070.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0502/6647/2631/files/demetuzafugub.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0496/1665/0389/files/kaliminiwowurojugela.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b3d9abdb-1764-4849-b84f-bfee3c110146/wimivalot.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8ba26270-de52-480e-9565-655b19357eb0/vemibonubasugipokulij.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_off0000628c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x628C 5424 bytes
SHA-256: 706598b4cfb5a39e0cb4e08bf0409743500114c95e2cd16b590a59f7b6339e97
font_01_sfnt_off000074cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x74CC 9852 bytes
SHA-256: 64467281c57f7a8dcace87176e5c9a801f03e2a3d776b54cfd15b26e2ec7013f
font_02_sfnt_off00009687.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x9687 4324 bytes
SHA-256: ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3

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