Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a4e4e5b5c39b308…

MALICIOUS

PDF

110.8 KB Created: 2021-09-09 07:46:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1561311af565a7adebf7cb0adf88e0df SHA-1: 1098d38cb4ad05150ff7546b7c47ea39c5f1aab2 SHA-256: 8a4e4e5b5c39b308a75bc7c3465cb5befb9764a2c974fbdfc127cda22cd7331c
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm on disposable hosting, with numerous embedded URLs pointing to other PDF files, suggesting a multi-stage download or phishing campaign. The presence of a 'download button' lure further supports this. No scripts were extracted, but the overall structure points to a malicious document designed to redirect users to external, potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://zhjpharm.com/upload/files/90471641533.pdf In PDF document text
    • http://share-world.tw/userfiles/file/51744134114.pdfIn PDF document text
    • http://chunmianxian.com/upfolder/e/files/20210901100311.pdfIn PDF document text
    • http://iehyun.com/editorupload/file/vulubirazusufowit.pdfIn PDF document text
    • http://hfnhsw.com/upload/files/70518650553.pdfIn PDF document text
    • http://massimobertoarchitetto.com/userfiles/files/pezilukepazikanoganelulo.pdfIn PDF document text
    • http://gruppocreta.com/userfiles/files/91235687869.pdfIn PDF document text
    • http://kunjipsc.com/uploads/files/rabugenataboxawidipasaj.pdfIn PDF document text
    • https://congnghieptauthuyvietnam.vn/upload/files/36891543185.pdfIn PDF document text
    • http://dellalontra.it/userfiles/files/26272703405.pdfIn PDF document text
    • http://launensia.cz/ckfinder/userfiles/files/surakiwovokodavodup.pdfIn PDF document text
    • http://cke.hk/userfiles/kunawijexazuwe.pdfIn PDF document text
    • http://skomi.ru/img/files/file/31686853377.pdfIn PDF document text
    • http://www.dfdtrading.sk/ckfinder/userfiles/files/55906522229.pdfIn PDF document text
    • http://tech-sub.com/userfiles/file/81645841349.pdfIn PDF document text
    • http://studiotecnicoligioni.com/userfiles/files/buwipaxesuxulav.pdfIn PDF document text
    • http://vo23.ru/upload/file/zatulasedimirujob.pdfIn PDF document text
    • https://needlugs.com/userfiles/files/26943487150.pdfIn PDF document text
    • https://kaowei.tw/image/files/20210905_121811.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ef2017dca3---25944922775.pdfIn PDF document text
    • https://careerexpo.alljobsinliberia.com/ckfinder/userfiles/files/40817941119.pdfIn PDF document text
    • http://izumrud38.com/ckfinder/userfiles/files/49778330175.pdfIn PDF document text
    • http://gatewayhotelbangkok.com/upfile_hotel/files/nenakalipupubanezumekeze.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=swords+and+sandals+2+unblockedPDF 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_off00013fe5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13FE5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000157f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x157F7 22704 bytes
SHA-256: c220b58e9281916aaf17177bbcf1758cd85251e9baa5ec48c165bd3f9d2ac02c
font_02_sfnt_off00019433.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19433 10784 bytes
SHA-256: 7256e98a52c7bef0513510f34f32f88cedf5b7c20009c559140b0888f9d9f40f