Malicious PDF — malware analysis report

Static analysis result for SHA-256 87631a8f11c0a89c…

MALICIOUS

PDF

81.5 KB Created: 2021-09-20 23:28:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 8a63a9b2acfd664571f2d764aeed737c SHA-1: f4c3a977b199c89e2a7b0f97292d703fa19ea5fb SHA-256: 87631a8f11c0a89ca7f4401c13059c9583877d4c353443e2f96a7c24d28c48f5
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for exploiting PDF vulnerabilities or redirecting users to malicious sites. The presence of numerous external URIs, many pointing to disposable domains, and a high ML classifier score strongly indicate malicious intent, likely for phishing or malware delivery. ClamAV also detected this as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 http://train-in-japan.com/images/blog/file/43929924249.pdf In PDF document text
    • https://afmiletisim.afmiletisimajansi.info/resimler/files/lutapedazawatel.pdfIn PDF document text
    • http://savvyais.com/userfiles/file/19955236430.pdfIn PDF document text
    • http://bainihu.com/upfiles/editor/files/83821495521.pdfIn PDF document text
    • https://www.assofmt.org/ckfinder/userfiles/files/31511159077.pdfIn PDF document text
    • https://jdrum-music.com/uploads/ckfiles/files/werovirikufenunose.pdfIn PDF document text
    • https://widepolymers.com/userfiles/file/79597553254.pdfIn PDF document text
    • http://divapharma.com/uploaded/file/sagitibi.pdfIn PDF document text
    • http://abwninemile.com/uploads/files/roxud.pdfIn PDF document text
    • http://1qjd.com/upload/files/2021-09-17-14-17-13-lW5Mrall.pdfIn PDF document text
    • http://naturabliskociebie.pl/userfiles/file/najafasutikusamulev.pdfIn PDF document text
    • http://alanaf.ru/userfiles/files/40613641474.pdfIn PDF document text
    • https://produktybhp.pl/pliki_user/File/34953927997.pdfIn PDF document text
    • http://ateliergermain.club/sites/default/files/file/nawudasomabolud.pdfIn PDF document text
    • http://www.multigacos.com/admin/uploaded/fck/file/87994137548.pdfIn PDF document text
    • http://shopgraeagle.com/ckeditor/uploads/files/dedukuv.pdfIn PDF document text
    • http://epoch-making.jp/js/upload/files/31927778259.pdfIn PDF document text
    • http://refah4ter.info/basefile/hotelrefah4terir/files/xexeniwomubigutiputin.pdfIn PDF document text
    • http://embeddedhr.com/ckfinder/userfiles/files/84768067664.pdfIn PDF document text
    • https://vanchuyenduongsat.vn/upload/files/82223383489.pdfIn PDF document text
    • http://modernplating.com/userfiles/file/nebasafejasuvuselubalesik.pdfIn PDF document text
    • http://captaincook.hu/userfiles/file/62118552982.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/23949209873.pdfIn PDF document text
    • http://bienbao.net/uploads/files/lawedavibudasitediwiki.pdfIn PDF document text
    • http://lisaarkinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/bezokuvepubifom.pdfIn PDF document text
    • http://goodfortune.hk/UpLoadFile/file///59089142077.pdfIn PDF document text
    • http://avandcie-energy.fr/ckfinder/userfiles/files/8891921661.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=redstone+book+pdfPDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d99d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD99D 10368 bytes
SHA-256: 9c7eb8e42c6bda2fd2f8b13774b52a49e8b9111442809758c7d62675bf101e03
font_01_sfnt_off0000f0fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0FC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001090e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1090E 17772 bytes
SHA-256: 6c0d645746e044f64521c6256611deaafd83cf97cca715eb5f11b82bb064a758