Malicious PDF — malware analysis report

Static analysis result for SHA-256 5667f508e78cdfaa…

MALICIOUS

PDF

84.1 KB Created: 2021-09-13 03:16:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 77cb27ed64dc1a4111260ec01e168ac2 SHA-1: 71305c423b9d913e7c7cdfe32bf0d032af71e041 SHA-256: 5667f508e78cdfaaac1628a80fe78eb68cb86c42b64fd48f65ef351d99686402
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised CMS uploads or disposable hosting. The embedded URLs and the overall structure suggest an attempt to lure users to malicious sites, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://cdmsig.com/ckfinder/userfiles/files/tafinin.pdf In PDF document text
    • https://newegys.egyseg.eu/ckfinder/userfiles/files/wejewob.pdfIn PDF document text
    • https://holcom-wd.holcom.vn/webroot/img/files/wikefatusofibasixixoba.pdfIn PDF document text
    • https://selispin.com/calisma2/files/uploads/wejewej.pdfIn PDF document text
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613356c30b8ed---48168173063.pdfIn PDF document text
    • https://mygamedaysports.com/wp-content/plugins/super-forms/uploads/php/files/fa5f3bb5c59eeb026f16d3cb46d62ab1/97405599515.pdfIn PDF document text
    • http://studiofapas.it/userfiles/files/4170702987.pdfIn PDF document text
    • http://vividconcept.in/userfiles/file/21705664.pdfIn PDF document text
    • http://packamate.com/userfiles/199809057.pdfIn PDF document text
    • http://codienlanhtrangia.com/Images_upload/files/59510855624.pdfIn PDF document text
    • http://afghansolar.com/userfiles/file/jozefuledotepoluv.pdfIn PDF document text
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/7dfb06a14ead873e54235d5ea437b90a/fijonulipugibevejibexab.pdfIn PDF document text
    • http://almawred-sy.com/files/adminfiles/files/50791159810.pdfIn PDF document text
    • http://modern-pro.ru/files/file/pelevadudokovizi.pdfIn PDF document text
    • https://conexusinternational.com/ckfinder/userfiles/file/45186399501.pdfIn PDF document text
    • http://nprofit.hk/userfiles/57877261684.pdfIn PDF document text
    • http://licausi.it/userfiles/files/vagasirefimu.pdfIn PDF document text
    • http://pate4me.com/userfiles/file/vinepopiwebesibulidatil.pdfIn PDF document text
    • https://sadex.pl/fck/file/rusavonuxebuwunetuvis.pdfIn PDF document text
    • http://michalpavlicek.com/uploaded/file/42464427680.pdfIn PDF document text
    • http://ferramentabelleggia.it/public/file/91085709555.pdfIn PDF document text
    • http://razaviota.ir/basefile/razaviotair/files/geravipisuziluvaxez.pdfIn PDF document text
    • http://sieuthihatgiong.vn/webroot/img/files/kofituporatelefu.pdfIn PDF document text
    • http://aptekainternetowa.net/_mdm_apteki/file/79242083635.pdfIn PDF document text
    • http://hoshitorionline.com/uploads/files/pezisibur.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=fake+call+pro+apkPDF 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_off0000dbf7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBF7 9972 bytes
SHA-256: f9514944b685277b38c435f3ca7ea5c2c23b35730abb8a1eb7823f39f3cdef34
font_01_sfnt_off0000f227.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF227 21732 bytes
SHA-256: cd1e551b6e0db9d37678b851006aa8dd8a0e721a08489ea7c2cc6892679d14ca
font_02_sfnt_off00012ae3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AE3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1