Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c157c59397924cd…

MALICIOUS

PDF

73.4 KB Created: 2021-09-17 04:52:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 84c2a75a8288eb64a12f5f2d9a90e2e5 SHA-1: 26c863fc3924d29b9d675c9582d137aa25a3e25f SHA-256: 5c157c59397924cd6ffe018405b9e4c2c0d55d8c0b8ad1d678b6441806762327
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The file contains numerous embedded URLs, many of which point to compromised websites or disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of these links and the overall structure indicate a phishing or credential harvesting attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://makojudo.pl/zdjecia/fck/file/jinixewo.pdf In PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138d884e0e18---88853488596.pdfIn PDF document text
    • http://se-ty.ru/uploads/userfiles/file/xuzovaka.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16133dc7f86e1b---60535972763.pdfIn PDF document text
    • http://school19-zav.ru/userfiles/file/8896832318.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613b19437fa3d---12171442673.pdfIn PDF document text
    • http://icoenergia.com/userfiles/files/74699881445.pdfIn PDF document text
    • http://togul.org/sites/default/files/file/ximadudopokupapofoder.pdfIn PDF document text
    • http://stellamaris.cz/userfiles/76504094404.pdfIn PDF document text
    • http://ppogrimall.com/upload/editor_image/file/24256571502.pdfIn PDF document text
    • https://zagi.hr/files/fakox.pdfIn PDF document text
    • https://atlastoursntravels.com/userfiles/file/1061746612.pdfIn PDF document text
    • https://radiosmile.hu/upload/file/dabiton.pdfIn PDF document text
    • http://ediljolli.com/userfiles/files/87225361509.pdfIn PDF document text
    • https://bk.knu.ac.kr/ckfinder/userfiles/files/navategesokunanikos.pdfIn PDF document text
    • http://santehnika34.ru/images/file/765322329.pdfIn PDF document text
    • http://dxline.eu/userfiles/file/kajodopesifudewaw.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f506b461d1---lovuvejarujez.pdfIn PDF document text
    • http://uleshuzatshop.hu/files/file/nakujuzivis.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=blue+tick+copy+and+pastePDF 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_off0000bbc0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBBC0 17028 bytes
SHA-256: d4af0bc9994ecb32f292ec4eb45a56a1e4c5837964347a10120475d377d49631
font_01_sfnt_off0000e775.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE775 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ff8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF8C 10764 bytes
SHA-256: ddf8e2d7256fb229246ae2aa56d967f275cf970f0457577a3fcc6a7d2feee285