Malicious PDF — malware analysis report

Static analysis result for SHA-256 827b9c59c3553a5a…

MALICIOUS

PDF

73.3 KB Created: 2021-02-14 07:25:03 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f252adf98a35e1474833abf769ba19c5 SHA-1: 5acc51bafeeb04f2ad4ea83be8c95295c4f20c03 SHA-256: 827b9c59c3553a5aecd0f194f469cffd54260e8093e00d222b0127c3db194c36
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to SEO-optimized PDF files, suggesting a link farm or phishing campaign. The ClamAV detection and ML classifier strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and extensive external linking are indicative of a spearphishing attachment designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://jacksth.ru/wix?keyword=lesco+spreader+parts+manual
    • https://static.s123-cdn-static.com/uploads/4475847/normal_5ff0373a6a823.pdf
    • https://static.s123-cdn-static.com/uploads/4487903/normal_5fef574bb14fc.pdf
    • http://save50.pro/85671709299gy1pv.pdf
    • https://static.s123-cdn-static.com/uploads/4383128/normal_5ff52b4fc3cca.pdf
    • https://static.s123-cdn-static.com/uploads/4464865/normal_5fcba221b1f60.pdf
    • https://static.s123-cdn-static.com/uploads/4366662/normal_5fc7bbc6992f3.pdf
    • https://tugigoboz.weebly.com/uploads/1/3/4/4/134499705/natibenasogaz-sodivudapexo-nukusatatipaki-takofowurepixes.pdf
    • https://static.s123-cdn-static.com/uploads/4456377/normal_60036e949af8a.pdf
    • https://static.s123-cdn-static.com/uploads/4493602/normal_5fed0a5518a28.pdf
    • http://tehnopolis.org/51098650312cnmf5.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/liwafo/lovubegomepepakimi.pdf
    • https://s3.amazonaws.com/ruzaganog/72648898000.pdf
    • https://s3.amazonaws.com/tuxenipup/woforameri.pdf
    • https://s3.amazonaws.com/kefodek/new_bollywood_full_movie_2019_filmywap.pdf
    • https://s3.amazonaws.com/wiwamoxamo/magujo.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d837.bin
710ada9d484a74473a9af4b16f00b3a2b91e4f606c36201a5d16255296ed0027
pdf-font-stream PDF embedded font (sfnt) at offset 0xD837 5160 bytes
font_01_sfnt_off0000e9b1.bin
04d61dd5462e11e708916138dc49cc84745c7807e0007bb9e4017a60be4b43ab
pdf-font-stream PDF embedded font (sfnt) at offset 0xE9B1 15308 bytes