Malicious PDF — malware analysis report

Static analysis result for SHA-256 521ebbc53976044e…

MALICIOUS

PDF

70.3 KB Created: 2021-09-26 00:00:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 3046e9f233b1036a40f8eeef3be3f097 SHA-1: 06527bb198ffacb3933f82cd88fb2057e3bd5584 SHA-256: 521ebbc53976044e5843558fdf9272c7087f3c777642a7c74b864480411e025b
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection for Pdf.Phishing.Trojan and an ML classifier indicating maliciousness. The presence of numerous embedded URLs, many pointing to potentially disposable hosting, suggests a link farm designed to redirect users to malicious content, consistent with phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and embedded links are indicative of an attempt to exploit users via external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://kleinschadenexperte.de/userfiles/file/24665707499.pdf In PDF document text
    • https://rocksoliddesigns.biz/userfiles/file/pupanus.pdfIn PDF document text
    • http://nagyberki.hu/sites/default/files/fck_uploads/file/vapovu.pdfIn PDF document text
    • http://geofer.eu/userfiles/files/nobefijoxavim.pdfIn PDF document text
    • http://fandimnarodaku.cz/upload/file/84539863345.pdfIn PDF document text
    • http://yanarfabrics.com/firma/files/daboforurukereravagaziz.pdfIn PDF document text
    • http://dep14kirov.ru/userfiles/file/18887476961.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210915175937.pdfIn PDF document text
    • https://tiemhoamo.com/data/dulieu/files/53410057788.pdfIn PDF document text
    • http://bargiel.com.pl/ckfinder/userfiles/files/vugopejabifibikukir.pdfIn PDF document text
    • http://www.mueblesgamez.com/ckfinder/userfiles/files/sitoxadazamavuwafanegexo.pdfIn PDF document text
    • https://isleo.com/i_photos/file/89729316321.pdfIn PDF document text
    • https://www.onestopnaturalstore.ca/wp-content/plugins/super-forms/uploads/php/files/a05j7qsog095jl8bcu22urro0p/80555821728.pdfIn PDF document text
    • http://gainliving.com/upload/editor/file/motulalomugewir.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161335be7da8d5---lafewisi.pdfIn PDF document text
    • https://legend-chang.com/UserFiles/files/bakupepalofe.pdfIn PDF document text
    • http://sriraghavendratemple.com/ckfinder/userfiles/files/kaxazoluwokatowiwi.pdfIn PDF document text
    • https://chameleoncoupons.com/adgprocessing/uploads/files/68607438922.pdfIn PDF document text
    • http://miryangpension.com/FileData/ckfinder/files/20210912_953883281473D7AE.pdfIn PDF document text
    • http://kubak-ubezpieczenia.pl/userfiles/file/bomefizolajedadagepiviv.pdfIn PDF document text
    • http://idcla.net/upload/files/77652319463.pdfIn PDF document text
    • https://atputasbazes.lv/images/userfiles/files/60715504291.pdfIn PDF document text
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/17509963878.pdfIn PDF document text
    • https://tidurmalam2.com/contents/files/xivalubaginemipulenabop.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=speak+out+intermediate+student%27s+book+answer+key+pdfPDF 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_off0000b0a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0A2 11252 bytes
SHA-256: d6798052b6fe94ee24e7966d19fd34faa56984a67054e65ca21802ca6358620d
font_01_sfnt_off0000caf1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAF1 15952 bytes
SHA-256: 78a1a1a63510fff24cc1e97d53f659b77ef62ea68b7f9692b982f3085f1248d8
font_02_sfnt_off0000f35a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF35A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1