Malicious PDF — malware analysis report

Static analysis result for SHA-256 a435f167b0ab063b…

MALICIOUS

PDF

76.5 KB Created: 2021-09-14 11:56:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: e931730470bea6b64fe1a212fe115ed2 SHA-1: 99028182c9563ab6c57ca779cd3cedf987ed5e1f SHA-256: a435f167b0ab063bafa7dbc9489a46be0028fdd72090317471e27cd6514c89ee
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that point to various domains, suggesting a link farm designed to redirect users to potentially harmful content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a deliberate attempt to obscure the final destination through multiple redirects.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 5

  • 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 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 http://madmojo.com/fckupload/file/39827821815.pdf In PDF document text
    • http://rheinmotel.com/userfiles/file/84503787501.pdfIn PDF document text
    • https://rougezenekar.hu/files/file/vezedorejajuvamuno.pdfIn PDF document text
    • http://avandcie-automation.fr/ckfinder/userfiles/files/16170079372.pdfIn PDF document text
    • http://caytrong.vn/Images_upload/files/38255809672.pdfIn PDF document text
    • https://cincia.ro/ckfinder/userfiles/files/jesuworuvomasuwebunesodu.pdfIn PDF document text
    • http://inggeo.eu/userfiles/files/3717162082.pdfIn PDF document text
    • https://gamaconsultores.cl/upload/file/ninowelemumoso.pdfIn PDF document text
    • https://fpcofmacon.com/nbloom/fckuploads/file/xakutanizimelukadoweraji.pdfIn PDF document text
    • https://edenestates.com/ckfinder/userfiles/files/22820235164.pdfIn PDF document text
    • http://www.binghan.my/userfiles/file/xokogizafifudonexinaga.pdfIn PDF document text
    • http://gibisch.org/files/files/32133678947.pdfIn PDF document text
    • http://promocode.lu/userfiles/files/jelalokuv.pdfIn PDF document text
    • http://nattukoottam.com/userfiles/file/30467556916.pdfIn PDF document text
    • https://anukulagrotech.com/userfiles/file/78598966858.pdfIn PDF document text
    • https://tommytest.dish1314.com/data/html_editor/files/86521724018.pdfIn PDF document text
    • https://digireg.nz/upload/gedifatewufo.pdfIn PDF document text
    • http://kameleonhastanc.hu/files/file/84237031098.pdfIn PDF document text
    • http://xn--80age2amlc.xn--80adxhks/pics/images/file/berinedanofonux.pdfIn PDF document text
    • http://homelife-superstars.com/image/files/60676427724.pdfIn PDF document text
    • http://iproperty.ae/userfiles/file/foxiloliki.pdfIn PDF document text
    • https://goodline.by/userfiles/file/luvosarekijimulutes.pdfIn PDF document text
    • http://sunnyten.net/userData/board/file/75996684992.pdfIn PDF document text
    • http://aloisiquadri.it/userfiles/files/52031969841.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=parallel+space+incPDF 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_off0000c91b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC91B 10152 bytes
SHA-256: 88e8ef7f8745e2b5c96dbfb62723144568d57aa202349100bb9c9c4be37f9237
font_01_sfnt_off0000dfdc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFDC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f7ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7EE 17424 bytes
SHA-256: f37e419c1f38264ba97202f28a4f25c7b32406fda18957cdcbd4c32901a7bdce