Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a38804e63854c52…

MALICIOUS

PDF

83.0 KB Created: 2021-09-08 13:09:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: fa9db4e42154220021146ff755a6577d SHA-1: f9e3c6fedb959277deb3d492437667a0e5b2027c SHA-256: 8a38804e63854c525c40ec3ecf631bf8b3f515b311b3a87813955a2755f9c723
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm and employs a social-engineering lure to trick users into installing browser extensions or updates. While no scripts were directly extracted, the nature of the lure suggests potential for JavaScript execution or exploitation to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://thieumaunao.vn/workspace/develop/uploads/ck_upload/files/42548760053.pdf In PDF document text
    • http://studionegro.net/userfiles/files/33507873448.pdfIn PDF document text
    • https://kampusogrenciyurdu.com/file/78372358475.pdfIn PDF document text
    • https://chambres-lannion.fr/userfiles/file/fagadozipajavapazosok.pdfIn PDF document text
    • https://copacndg.com/images/uploads/files/saweg.pdfIn PDF document text
    • http://gimhaejazz.com/fckeditor/userfiles/image/38979599164.pdfIn PDF document text
    • https://aymsoft.us/aym_image/files/87476510324.pdfIn PDF document text
    • http://doremimarlikinsaat.com/userfiles/file/woranewazufofozopibugefa.pdfIn PDF document text
    • http://dichvugiayphep.biz/upload/ck/files/18290309976.pdfIn PDF document text
    • http://viorina-deko.com/images/file/jukimebaden.pdfIn PDF document text
    • http://zavalinka.by/var/upload/file/93696932970.pdfIn PDF document text
    • https://rasathantrananotech.com/ckfinder/userfiles/files/83462956646.pdfIn PDF document text
    • http://xn--80ahcjevtqq.xn--p1ai/ckfinder/userfiles/files/nimijurevigowakafi.pdfIn PDF document text
    • http://foodchemsino.com/d/files/77574668530.pdfIn PDF document text
    • http://househouse.it/userfiles/files/merogulo.pdfIn PDF document text
    • https://pmcp-avac.com/files/upload-ckfinder/files/55982560774.pdfIn PDF document text
    • http://iaestedresden.de/userfiles/file/figesozozuwam.pdfIn PDF document text
    • http://congluc.com/upload/files/mufugobivuparobawoxin.pdfIn PDF document text
    • https://htchninc.com/d/files/tepusesegidotepibetulimaw.pdfIn PDF document text
    • http://axiomestates.com/userfiles/file/lonoronawobujorevigekufe.pdfIn PDF document text
    • http://hiroi-es.info/yamituki-n/uploads/files/4938097479.pdfIn PDF document text
    • http://ueros.fr/admin/ckfinder/userfiles/files/xurigagosazupurageki.pdfIn PDF document text
    • https://snapstudios.ca/userfiles/file/mulosuvexejiru.pdfIn PDF document text
    • http://finproekt-msk.ru/userfiles/file/damovedugi.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1613321639e943---kuwane.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=refining+precious+metal+wastes+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_off0000dd07.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD07 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f519.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF519 18284 bytes
SHA-256: e2622bf70de331e316793b5b38732af68e31139e014c5105838d5b1bfabc2d6e
font_02_sfnt_off0001240a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1240A 11196 bytes
SHA-256: ceca79e88e8c2835484efa2c2c918a7dc40ea1e4719a3394ce0e148c355773b6