Malicious PDF — malware analysis report

Static analysis result for SHA-256 231e538ef925b286…

MALICIOUS

PDF

69.8 KB Created: 2021-09-28 09:29:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c3debbf884b9d1752c3f13c1ad0c507b SHA-1: 0674d54dc58bcd429097e6ec4b8f481eccd94709 SHA-256: 231e538ef925b28620fe9d07484163cc291d66813a269edf103f80ccc3f90d34
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document flagged by ClamAV as a phishing trojan. It contains numerous embedded URLs, many of which point to disposable domains and are structured as a link farm, a common tactic for distributing malicious content or conducting phishing. The ML classifier also strongly indicated maliciousness. While no scripts were explicitly extracted, the PDF structure and embedded links suggest an intent to redirect users to malicious sites, likely for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • 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.
  • 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://didopack.com/files/pajoketizewa.pdf In PDF document text
    • http://nscenter.cn/upload/files/9288688657.pdfIn PDF document text
    • http://glavis.biz/userfiles/file/677937835.pdfIn PDF document text
    • http://52fotki.ru/ckfinder/userfiles/files/10430372003.pdfIn PDF document text
    • https://samirkumarpaul.com/ckfinder/userfiles/files/zawefexatodev.pdfIn PDF document text
    • https://mbzl-pro.xyz/web/img/podborky/files/35220080420.pdfIn PDF document text
    • http://letresorellebio.it/userfiles/files/36192431635.pdfIn PDF document text
    • http://kingtonkatsu.com/uploads/files/83780189165.pdfIn PDF document text
    • https://monyetmesum.com/contents/files/patibujubarafovidinaguwux.pdfIn PDF document text
    • https://uleiuri.ro/userfiles/file/bovepagelasisufijeve.pdfIn PDF document text
    • http://suvagcentr.ru/userfiles/files/rukibudobur.pdfIn PDF document text
    • http://sisparts.pl/zdjecia/fck/file/79939625350.pdfIn PDF document text
    • http://flapboxes.com/userfiles/files/83563259787.pdfIn PDF document text
    • http://21cedu.com/pds/userfiles/files/72179160415.pdfIn PDF document text
    • http://bowlingkillers.com/imgdb/files/48692924151.pdfIn PDF document text
    • https://amzentransportationindustries.com/admin/imagetemp1/file/ragogegulizadawe.pdfIn PDF document text
    • http://systemsbiology.at/uploads/assets/file/vugesezik.pdfIn PDF document text
    • http://caminodesantiagoenmoto.com/assets/ckfinder/core/connector/php/uploads/files/walewujofanapalame.pdfIn PDF document text
    • http://polenes.cl/userfiles/file/1398270310.pdfIn PDF document text
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/5d421509325673cc4db94eee5df17795/67156243592.pdfIn PDF document text
    • http://www.pranabkumar.com/fckimages/file/5915414647.pdfIn PDF document text
    • https://liur-krd.ru/userfiles/file/76651898543.pdfIn PDF document text
    • http://bjdfszwy.com/filespath/files/20210921211040.pdfIn PDF document text
    • http://nifaelectronics.com/userfiles/file/13748670190.pdfIn PDF document text
    • http://www.alfapilates.pl/upload/file/mosuzemutovupiwegafikuzog.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=snapdragon+460+octa+core+processorPDF 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_off0000b014.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB014 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c82b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC82B 10992 bytes
SHA-256: 967ed6deadd70f85f6e39ac3552cac04c4a350722dc077ab44b53d0ed7b6902a
font_02_sfnt_off0000e19a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE19A 15704 bytes
SHA-256: fe41a6f4bd7bd03cc27c3885d91143fe5938bd7f22770b924964d147fd3d1aab