Malicious PDF — malware analysis report

Static analysis result for SHA-256 331fbdabf9e252d7…

MALICIOUS

PDF

88.5 KB Created: 2021-09-16 18:19:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: d4831d6fe1ccc844b38527e7a38feb6a SHA-1: 67bab21a6788b9dbdb2bd852d0d21e4df9c396f7 SHA-256: 331fbdabf9e252d79f858924ffc7c49d0cc9bc188fe06b521255dc66549201f0
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The presence of numerous links pointing to disposable domains, coupled with the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic, suggests a phishing or scam campaign designed to redirect users to potentially harmful sites. While no scripts were explicitly extracted, the PDF structure itself contains embedded links that are characteristic of such attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://htapigroup3.com/contents/files/kozofofowekopazululiro.pdf In PDF document text
    • https://nidi.mk/ckfinder/userfiles/files/34448138512.pdfIn PDF document text
    • http://mobilenmr.com/files/files/47080799461.pdfIn PDF document text
    • https://foundationkuzmanov.com/files/pamafipurigosupirenulitix.pdfIn PDF document text
    • http://runnersavezzano.it/public/userfiles/file/gizinupuzebur.pdfIn PDF document text
    • http://imobilestore.de/userfiles/file/xujuxixeralamazenulosowi.pdfIn PDF document text
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/0193e73e7252f1bf9c01944f20d516e8/78029831089.pdfIn PDF document text
    • https://cncunse.com/d/files/wasanusale.pdfIn PDF document text
    • http://chinajessie.com/seadata/data/uploads/img/file/163155404849.pdfIn PDF document text
    • http://wujipacking.tw/upload/files/ladinudimekuj.pdfIn PDF document text
    • http://c2ctrading.org/cms_upload/files/9509138409.pdfIn PDF document text
    • http://kompassztuki.pl/Image/files/semizojamu.pdfIn PDF document text
    • http://dailynewsodia.com/assets/ckfinder/core/connector/php/uploads/files/kudekofibogejitusum.pdfIn PDF document text
    • http://divorcefinance.nl/uploads/file/vuwimujewatarulotem.pdfIn PDF document text
    • http://ksiclubcom.ksiclub.org/svnprojects/DHD/Source/images/files/fuwaxafokawifu.pdfIn PDF document text
    • http://cofetariafraguta.ro/UserFiles/file/dowozur.pdfIn PDF document text
    • https://samarthanamparisara.org/apadmin/uploads/userfiles/files/xuzevigatetezu.pdfIn PDF document text
    • http://dolphinkorea.com/files/files/64076022191.pdfIn PDF document text
    • http://pereplanirovkaoblast.ru/pict/file/lojozololuko.pdfIn PDF document text
    • http://bestbelly.org/content/files/files/xifusikim.pdfIn PDF document text
    • http://www.grundys.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161336810d6275---dewopimexasexetabi.pdfIn PDF document text
    • http://delfosventures.eu/userfiles/files/kokizonis.pdfIn PDF document text
    • http://dralituncer.com/userfiles/file/sekexipuxilofuvona.pdfIn PDF document text
    • http://autavrabek.cz/obrazky/file/21222042855.pdfIn PDF document text
    • http://otczenacts.com/media/files/5780195443.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=android+box+resetPDF 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_off0000f557.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF557 10256 bytes
SHA-256: 9c2a41293750a5f49151fb27ab25bd942bc18d69840303596a56d1ab9986f90e
font_01_sfnt_off00010c8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C8A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001249c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1249C 18636 bytes
SHA-256: 6c006beca593d77d736077a7235c1175be05e968ecac1f9664a92aeadcaf936f