Malicious PDF — malware analysis report

Static analysis result for SHA-256 b56f768a1c5e84cf…

MALICIOUS

PDF

84.8 KB Created: 2021-09-16 19:30:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 90aae622f257a823636fc091673b34b5 SHA-1: 2024e5d27f0c9df5b44021d1403aec7775246d69 SHA-256: b56f768a1c5e84cfaeb458384411c4479efae0d8641a8a92a5e7328abce63ccb
134 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The presence of numerous external URIs, including those on potentially disposable hosting, suggests a phishing or credential harvesting campaign. The heuristic 'SE_DOWNLOAD_BUTTON' further supports a lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://xosobacninh.vn/webroot/img/files/dulujekoriz.pdf In PDF document text
    • https://mabuksusu2.com/contents/files/95651384709.pdfIn PDF document text
    • http://bytip.net/filespath/files/20210906013520.pdfIn PDF document text
    • http://noavarservice.com/ckfinder/userfiles/files/56398320814.pdfIn PDF document text
    • https://washlounge.in/ckfinder/userfiles/files/4276432593.pdfIn PDF document text
    • http://abwmarlboropike.com/uploads/files/zokelipodamajitozux.pdfIn PDF document text
    • http://language-coach.pl/uploads/files/xuseroz.pdfIn PDF document text
    • http://computerdoki.hu/user/file/48409160148.pdfIn PDF document text
    • http://sbcnepal.com/images/file/wilexaponowisiginolotoj.pdfIn PDF document text
    • https://www.cosanuesa.com/componentes/editor/ckfinder/userfiles/files/dogutezivenepumoxezejuge.pdfIn PDF document text
    • https://rolcsi-bau.hu/userfiles/files/76990636643.pdfIn PDF document text
    • http://qiuyutv.com/userfiles/files/20210911052332.pdfIn PDF document text
    • http://tomaszskiba.com/userfiles/file/pesijelogoxululowajuvaja.pdfIn PDF document text
    • https://lecachet.fr/docs/files/labegezegeluk.pdfIn PDF document text
    • http://pepinieres-soupe.com/userfiles/file/zudufubogefas.pdfIn PDF document text
    • https://gegeny.hu/uploads/file/55541829680.pdfIn PDF document text
    • http://trans-serwis.com/userfiles/file/65916487276.pdfIn PDF document text
    • https://sysyanginguvenlik.com/uploads/files/wuvexebenujuma.pdfIn PDF document text
    • https://bloomlight.pl/_bloom/file/ramikurasolomi.pdfIn PDF document text
    • http://studiomontironi.eu/userfiles/files/bofotozazuroxerofokazikag.pdfIn PDF document text
    • http://kapfenberger-schuetzenverein.at/userfiles/file/sudogolep.pdfIn PDF document text
    • https://wilocom.ro/ckfinder/userfiles/files/soxones.pdfIn PDF document text
    • http://greatwalledmond.com/ckfinder/userfiles/files/zebolizukabaxulenoxenedo.pdfIn PDF document text
    • http://aire-limpio.com/img/editor/file/6758239572.pdfIn PDF document text
    • http://gachmenminhchien.com/media/ftp/file/93408981154.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=ubuntu+adb+fastbootPDF 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_off0000e3fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3FE 10224 bytes
SHA-256: 8d47f894f945cab7cb98b6ffae1f8a563cbac9077e3117c3515ce8cc55cf8889
font_01_sfnt_off0000fb16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB16 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011328.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11328 19148 bytes
SHA-256: 2e47a26edaee71d77a821d9d6137af2d442d2c1dc4d3a34ceff1705a1cd60837