Malicious PDF — malware analysis report

Static analysis result for SHA-256 28c8f4c238c1f051…

MALICIOUS

PDF

68.7 KB Created: 2021-10-02 14:02:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c1bb034a71f3751cd3a995eb064a055f SHA-1: 973803e75ee64d1beb11faf7e05ca32a687d5f99 SHA-256: 28c8f4c238c1f051a8822cbb2e98db4dc9f8d6c90401d0dc275ac80335589cd4
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF is identified as a phishing lure due to its image-only nature and embedded clickable link. Heuristics indicate it's a link farm on disposable hosting, suggesting a phishing campaign. The ML classifier and ClamAV detection strongly support its malicious classification. No scripts were extracted, but the presence of external URIs points to a likely attempt to redirect the user to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 1 image(s), only 0 text block(s), carries a click-outward action, and is only 68 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • 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://wastran.ru/uplcv?utm_term=tell+me+why+should+i+hire+you PDF link annotation
    • http://absolutelyneon.com/userfiles/file/23095513076.pdfIn PDF document text
    • http://1855-4080.com/userfiles/file/rorosifofowamudutazo.pdfIn PDF document text
    • https://burragebrothers.com/demo/jolie/beta/userfiles/files/52761955696.pdfIn PDF document text
    • http://boschvietnam.vn/files/usersfiles/files/zakeguwubikix.pdfIn PDF document text
    • https://ksmt.edu.np/assets/ckfinder/userfiles/files/valivolodegi.pdfIn PDF document text
    • http://eg-connect.com/uploads/editorfiles/file///jixamibuzagaloliz.pdfIn PDF document text
    • http://yasaitogo.com/uploads/files/57843438144.pdfIn PDF document text
    • http://encino.ilovepokebar.com/uploads/files/ditevo.pdfIn PDF document text
    • https://letstravelforacause.com/miet/assets/files/dabaxodivuwofume.pdfIn PDF document text
    • https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/eg386otkf5r8bng2lfdq2g85hu/2731412356.pdfIn PDF document text
    • https://booknowrentalimo.ch/userfiles/files/38385628272.pdfIn PDF document text
    • http://www.pes.edu.mn/ckfinder/userfiles/files/jeriwaxavuju.pdfIn PDF document text
    • https://taptigrihnirman.com/singhania/downloads/file/zuzafosewivi.pdfIn PDF document text
    • https://www.dooleysnaturalgas.com/ckfinder/userfiles/files/28449658974.pdfIn PDF document text
    • https://kstraders.com/userfiles/file/41353115871.pdfIn PDF document text
    • http://cbstav.cz/file/zaxawajapo.pdfIn PDF document text
    • https://kingdomdatesuae.com/userfiles/files/tapij.pdfIn PDF document text
    • https://esz.jp/img/editor/files/14697329898.pdfIn PDF document text
    • http://labellebeaute.com.hk/ckfinder/userfiles/files/sakipevokikoxitupim.pdfIn PDF document text
    • http://ondamarinarest.com/upload/files/6148806039.pdfIn PDF document text
    • http://keletunderground.hu/images/uploaded_pics/file/5472320633.pdfIn PDF document text
    • http://ssaisarang.com/ckfinder/userfiles/files/levefigitadugexedunuzin.pdfIn PDF document text
    • http://abwlanham.com/uploads/files/miviwuzulupazaruzama.pdfIn PDF document text
    • http://systemsbiology.at/uploads/assets/file/bagoxon.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_off0000b25f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB25F 14112 bytes
SHA-256: cbe7cca088e0698d3095237d1735269660f26700404f3df75c4194f87444086a
font_01_sfnt_off0000d57f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD57F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ed96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED96 10412 bytes
SHA-256: 3362d85742b1826af2d46bd483b6ea8c6494efee2622962d6217d9940f94d221