Malicious PDF — malware analysis report

Static analysis result for SHA-256 87745e9f5d246b1d…

MALICIOUS

PDF

72.3 KB Created: 2021-09-09 00:31:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c27a0cd07e90ec9c403425db978c8a1c SHA-1: 9f296125aca2dbaf374ff3cb971fc157bca666e1 SHA-256: 87745e9f5d246b1dada0ef83eca161b11fe76b0d8341c7d6a2f38ab3d8ee26cc
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple external URIs and is flagged as a link farm on disposable hosting, indicating a malicious intent to redirect users. The ML classifier and ClamAV detection strongly suggest this is a phishing or malware distribution document. No scripts were extracted, but the PDF structure itself facilitates the attack by hosting numerous links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://olterus.info/contents/files/gasinegojo.pdf In PDF document text
    • https://ambulatorioveterinariosismondi.eu/file/watebibumojapagofof.pdfIn PDF document text
    • http://copingconversations.com/userfiles/file/ripav.pdfIn PDF document text
    • https://emtracing.net/userfiles/file/72911000538.pdfIn PDF document text
    • http://hyundaidongdo3s.com/images/files/fiwuro.pdfIn PDF document text
    • https://abouelhoulgroup.com/userfiles/files/89367967795.pdfIn PDF document text
    • http://verynailscm.com/user_img/file/gitoraroriniroxugogajut.pdfIn PDF document text
    • http://chickenwild.com/upload/contents/images/images/63965344259.pdfIn PDF document text
    • http://askort.pl/Upload/file/74759222034.pdfIn PDF document text
    • http://dientrotiendathc.com/media/ftp/file/rituluwuxizefi.pdfIn PDF document text
    • https://marlin-aquarium.ru/ckfinder/userfiles/files/famokix.pdfIn PDF document text
    • http://bioident.pl/photos_fck/file/91974965304.pdfIn PDF document text
    • http://re-media.ru/foto/ck/files/lovetojalito.pdfIn PDF document text
    • http://easyliveconstruction.com/ci/userfiles/files/83237635645.pdfIn PDF document text
    • http://munnarteabungalows.com/userfiles/file/95455851306.pdfIn PDF document text
    • http://beiwendq.com/data/attachment/file/xomefegakididep.pdfIn PDF document text
    • http://sherwoodchambergolf.com/ckfinder/userfiles/files/91368461191.pdfIn PDF document text
    • http://ailizia.com/userfiles/tabedasopakodisepejufum.pdfIn PDF document text
    • http://massvt.sk/editor_uploads/system/files/86429530949.pdfIn PDF document text
    • http://zoncmswebsitebeheer.nl/files/editor/file/luzotasomatadok.pdfIn PDF document text
    • http://benthanhsgfarm.net/images/uploads/files/genojarumigiveletamove.pdfIn PDF document text
    • http://zensushidanapoint.com/uploads/files/xojigosazijat.pdfIn PDF document text
    • https://www.tri-or.fr/tri-or/ckfinder/userfilesfiles/gugexevosow.pdfIn PDF document text
    • http://rovitek.com/userfiles/file/25039870203.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=snes+online+switchPDF 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_off0000b3ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3AB 10224 bytes
SHA-256: 9d1f4b9e3c8d9609d5bb24e3530d2681816adb9e4479d4e1fb0ef2f860c7c554
font_01_sfnt_off0000ca96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA96 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e2a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2A8 19716 bytes
SHA-256: c972160696403bb201b5c666841a8d0ffdf46ddcac7af828b3659c506241ab4a