Malicious PDF — malware analysis report

Static analysis result for SHA-256 990de4e42cea0855…

MALICIOUS

PDF

82.0 KB Created: 2021-05-31 05:07:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-22
MD5: b5ce909faa3e2f85e8ac0194d7bd2b8a SHA-1: db9739fdf4175e3c28097f22ad5dbf65f114af6f SHA-256: 990de4e42cea0855f923d0a46d654236a51524dbb741f3bc94f60345b62079f5
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 0.9997

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://druttle.ru/strik?utm_term=adecco+salary+guide+2020+singapore PDF link annotation
    • https://wapexuji.weebly.com/uploads/1/3/5/3/135329723/linitineraguliv.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4422909/normal_6068f15b770fd.pdfIn PDF document text
    • https://vematonejos.weebly.com/uploads/1/3/1/3/131383464/rexutimekojuwafa.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4388063/normal_5fc9baa783da4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4464871/normal_601bfcdb89133.pdfIn PDF document text
    • https://zugudomumomaxix.weebly.com/uploads/1/3/5/3/135324912/658a4ae95357293.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4490528/normal_5fe5a522c05df.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478928/normal_604fb92843df4.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4454422/normal_6004ddc384c13.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450428/normal_6042fcc1a5c51.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4444884/normal_5fcce55349406.pdfIn PDF document text
    • https://xudidetopos.weebly.com/uploads/1/3/4/5/134579215/vedezagonapile-nonokodixinu-kododibu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393485/normal_6012ca28818e6.pdfIn PDF document text
    • https://dunebuka.weebly.com/uploads/1/3/2/6/132682868/molosurutefu_wiroke.pdfIn PDF document text
    • https://fuvipizewovotat.weebly.com/uploads/1/3/1/0/131069886/9597342.pdfIn PDF document text
    • https://wilexezixokesu.weebly.com/uploads/1/3/4/7/134764798/30943371b19e6.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/2ce8ea60-f8d0-4225-b22b-7897a7b2e59e/gta_liberty_city_stories_apk_obb_download_lite.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/34dbe9ee-2622-43ea-a4c0-a0f055735139/1333372453.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a33afe8b-0d58-4a56-a935-b199d3614a09/jogidarupebawuresawugoj.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5c07d695-485e-4bf0-8e82-82233bc7d8c0/96507056692.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_off0000e98d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE98D 5604 bytes
SHA-256: 7a6637c44376cd4367414ec850b9268be3342bfe6530e978bc91f4cad57576bb
font_01_sfnt_off0000fcb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCB1 11408 bytes
SHA-256: 5e8110d602e6dbefbcfea0dc4f964866610d5fb0aad6dfe03a5d8d2e70489f4d
font_02_sfnt_off0001131b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1131B 11472 bytes
SHA-256: f90d6d85b10c34f22dff929abd206e0b1f98815cc8d92642f22b44ab51cd46d1