Malicious PDF — malware analysis report

Static analysis result for SHA-256 c926e409143ddf95…

MALICIOUS

PDF

83.5 KB Created: 2021-09-11 06:04:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 2d5e6e2adf4dc0928ec371cfdee25a37 SHA-1: 3dd42d98a529a61147838f03db41a08889ac971d SHA-256: c926e409143ddf95ddce842c4486443862141750f917c51ea3ccd83b42301c6c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to PDF files on various domains, suggesting a link farm or redirection mechanism. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a strategy to obscure the ultimate destination. While no scripts were explicitly extracted, the nature of the embedded URLs and the PDF format itself often implies the use of JavaScript for exploitation or redirection, hence T1059.007 is included.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 https://fasleh.net/Files/files/luzad.pdf In PDF document text
    • https://es21sys.com/userfiles/file/tewesesonujalodezipumoket.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/jimugidelimon.pdfIn PDF document text
    • https://highfieldhousehotel.net/nbloom/fckuploads/file/bowiwemomuf.pdfIn PDF document text
    • http://infoegrafica.com/userfiles/files/26005356341.pdfIn PDF document text
    • https://swaarm.de/app/webroot/upload/files/63327427685.pdfIn PDF document text
    • http://scarpatti.com/files/xarodev.pdfIn PDF document text
    • http://robfredo.com/userfiles/file/61128816242.pdfIn PDF document text
    • http://hyosangjo.com/userfiles/file/20210906073743.pdfIn PDF document text
    • http://a-b-i-s.net/layout/bilder/file/60710988890.pdfIn PDF document text
    • http://hoya-system.com/uploads/files/202109110550118965.pdfIn PDF document text
    • http://radio-salsa.fr/php/rs/filesupload/file/fowedexate.pdfIn PDF document text
    • http://akademia-jedenastka.pl/zdjecia/fck/file/97320131127.pdfIn PDF document text
    • http://fongyoskert.hu/userfiles/files/47499528906.pdfIn PDF document text
    • http://aucoindeshalles.fr/menu/file/zukowenadezisakafosefux.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1612feef4da397---winusejelasu.pdfIn PDF document text
    • http://www.polni.si/Images/files/tekutu.pdfIn PDF document text
    • http://duonglaohanoi.com/userfiles/file/pewesebetedejupaf.pdfIn PDF document text
    • http://imobilestore.de/userfiles/file/bevafovisujepubusasoluvir.pdfIn PDF document text
    • http://graylegalservices.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/93591790966.pdfIn PDF document text
    • http://www.jysunshine-hotel.com/up_files/file/vevetugepafineromapibe.pdfIn PDF document text
    • http://kiko168.com/UploadFile/file/20210906073758380.pdfIn PDF document text
    • http://emke.hu/uploads/ckfinder/userfiles/files/rijazakigudoveji.pdfIn PDF document text
    • https://pinyardim.com/calisma2/files/uploads/junorivuvisinew.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=comparative+superlative+multiple+choice+test+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_off0000db94.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB94 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f3ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3AB 10976 bytes
SHA-256: c1189baccc6998b3222836ff2abcd947a1d48be49f1f5267535af060159a543f
font_02_sfnt_off00010d30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D30 19368 bytes
SHA-256: ed26987006755e3e6ba30312e67bbeb9b5b57237be20b707c702a666f8a0d25e