Malicious PDF — malware analysis report

Static analysis result for SHA-256 645384d8acac0daa…

MALICIOUS

PDF

77.8 KB Created: 2021-04-03 16:41:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: a7e03896016faa8d6575275486f54fd4 SHA-1: 4f9d0a1aa4546e2ee1a6e2bea8c059686104bb4e SHA-256: 645384d8acac0daa1891d220edf23444a6db051f1630edaa5883b1749d0fe880
186 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many hosted on disposable domains, suggesting a link farm or redirection scheme. The document body, though partially garbled, references "Sohcahtoa word problems hw answers", a common lure for educational content. The presence of PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics, along with a high ML_NYX_PDF_MALICIOUS score and ClamAV detection, strongly indicates malicious intent, likely to drive traffic to malicious sites or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://resalured.ru/wix?keyword=sohcahtoa+word+problems+hw+answers PDF link annotation
    • http://runivofo.iblogger.org/technical_drawing_with_engineering_graphics_15th_edition_solutions.pdfIn PDF document text
    • http://futup.ru/words_that_start_with_xenamqudg.pdfIn PDF document text
    • http://changely.club/38691933240y4h48.pdfIn PDF document text
    • https://cdn.sqhk.co/tibakekavero/icjjMtD/34063641088.pdfIn PDF document text
    • http://autobaff.xyz/toca_life_vacation_short_moviephihs.pdfIn PDF document text
    • https://cdn.sqhk.co/vovomafejuwa/hgv8iiO/guwufabimuvujipo.pdfIn PDF document text
    • http://alsamcctv.com/valobadogx44ls.pdfIn PDF document text
    • https://cdn.sqhk.co/rikopekela/qhghfhf/jowugagon.pdfIn PDF document text
    • http://buloshnaya.site/because_of_mr_terupt_book7fj31.pdfIn PDF document text
    • https://cdn.sqhk.co/xajevedu/uic7haI/foboforixiwax.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://kugilib.rf.gd/93838975703.pdfIn PDF document text
    • https://6376acfe-5884-4251-b3d5-19a03c044549.filesusr.com/ugd/de3d83_3318ff856a7c4259a599ae95f1e748f4.pdf?index=trueIn PDF document text
    • https://f50ece36-1901-4a7b-9396-968a400df7f4.filesusr.com/ugd/3ecb95_cf900345817044d286d8b6ab96d1433d.pdf?index=trueIn PDF document text
    • http://xulivef.rf.gd/95262908236.pdfIn PDF document text
    • https://8c56b32b-3398-45d6-9c0b-b55146621f16.filesusr.com/ugd/6924eb_b3c6c743040248b288ac85b06aea89db.pdf?index=trueIn PDF document text
    • https://cff07a16-13b2-455b-8a78-148a75b158b4.filesusr.com/ugd/cda0c7_5de2d3fb08d740909ecbc69a2ac3cd26.pdf?index=trueIn PDF document text
    • https://6376acfe-5884-4251-b3d5-19a03c044549.filesusr.com/ugd/de3d83_37448e398000402caf207c26daec6ce8.pdf?index=trueIn PDF document text
    • https://52a72965-a6d2-471e-b66a-59a59a4d663b.filesusr.com/ugd/e643da_1126aa06c05348ca91c0ab0bc144e48d.pdf?index=trueIn PDF document text
    • https://13a7c488-548c-4b48-b567-d2b0b9a3e1de.filesusr.com/ugd/85d67f_a573573a308f4583913b0417ec62a6ba.pdf?index=trueIn PDF document text
    • http://janaradoru.rf.gd/28890639166.pdfIn PDF document text
    • http://puzegekizizovin.epizy.com/cursive_writing_file.pdfIn PDF document text
    • https://03df18d0-0a94-4077-8b44-1f3cf8b7c870.filesusr.com/ugd/23a6c3_a70aaad3f1854f03b0e688beadacd7d8.pdf?index=trueIn 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_off0000ecaa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECAA 5648 bytes
SHA-256: f6a2c87a1d04ee8b0f1e800542cc0d129da45dcbd370dca9ce027b0db7a17324
font_01_sfnt_off0000ffbc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFBC 11776 bytes
SHA-256: dd5c0f1fbb0088657c3d0d29977c024e06da6db0dc5756621a6b865815449762