Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3f4287e8e684995…

MALICIOUS

PDF

78.4 KB Created: 2021-09-19 04:10:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 5f3de9416b424e39280614ffdca8abfd SHA-1: d52dd77cfde2de928cacbb34da1aeedb55e6c8e5 SHA-256: b3f4287e8e6849956a837e9964db0dd5258fc641136bcfd8eb905da3a543e574
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as a phishing trojan and by an ML classifier as malicious. It contains numerous embedded URLs that point to various domains, many of which appear to be disposable or used for hosting PDF files. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic indicates a deliberate attempt to create a link farm, likely to distribute malicious content or phish for credentials. Although no scripts were explicitly extracted, the nature of the PDF and the numerous external links suggest it is designed to redirect users to malicious sites, potentially for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • 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.
  • 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://huntic.ru/uplcv?utm_term=123+reg+webmail+android PDF link annotation
    • http://doktor-okonski.pl/uploadimg/file/70456009450.pdfIn PDF document text
    • https://bbpartner.cz/userfiles/file/33252984173.pdfIn PDF document text
    • http://hzkontejnery.cz/ckfinder/userfiles/files/fugutokajuba.pdfIn PDF document text
    • http://tatnhapkhau.com/ckfinder/userfiles/files/78169200656.pdfIn PDF document text
    • http://shiokuda1.com/contents/files/wipitiloxekezixadolota.pdfIn PDF document text
    • http://medi-sen.com/files/files/dufofelekevet.pdfIn PDF document text
    • http://xfswchem.com/upload/files/26942261323.pdfIn PDF document text
    • https://airxps.com/userfiles/files/5971590762.pdfIn PDF document text
    • http://feg.vn/uploads/files/41551993805.pdfIn PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/6c223370104156e65a03a052c94fcbae/99455863876.pdfIn PDF document text
    • http://jurabos.nl/include/editor/file/kuloribokedulurulile.pdfIn PDF document text
    • https://simondaulte.com/ckfinder/userfiles/files/dojododetitabokesipama.pdfIn PDF document text
    • http://werkkledingverkoop.nl/images/docman/files/94219683628.pdfIn PDF document text
    • https://sreekanakananda.com/ckfinder/userfiles/files/39061658999.pdfIn PDF document text
    • http://harringtonandlombardi.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/53222968630.pdfIn PDF document text
    • https://mariapolis.net/ckfinder/userfiles/files/kasufikisinuzujixojemisop.pdfIn PDF document text
    • http://autohondl.cz/userfiles/file/67139630544.pdfIn PDF document text
    • http://mini-garden.ru/userfiles/file/10849257199.pdfIn PDF document text
    • http://sgrappresentanze.eu/userfiles/files/47960078644.pdfIn PDF document text
    • https://autoskola-scp.com/files/suxewufemox.pdfIn PDF document text
    • https://mmgrowersg.com/ckfinder/userfiles/files/wugujukamebewut.pdfIn PDF document text
    • 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_off0000ce68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE68 17556 bytes
SHA-256: b2c5e61d7b004a25d2329f190b0991beaeea92a604b146dcf91482a6461fbe99
font_01_sfnt_off0000fc1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC1D 10796 bytes
SHA-256: f604ba3be471264d06da6d3fcf6567ba317c15b59652a1b7afc0f7d4a33feeed
font_02_sfnt_off000114d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114D7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1