Malicious PDF — malware analysis report

Static analysis result for SHA-256 eb428edf75d3e037…

MALICIOUS

PDF

71.2 KB Created: 2021-09-29 06:09:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 0b5b62aae516de8569f4a4c6b2fb1067 SHA-1: b1cf7dec89e67084503ccb19641e40c981cf9641 SHA-256: eb428edf75d3e03765f042855b7229df0c034ef82e7afb5bec7abafd9c99ba1f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous external URIs, with one heuristic specifically identifying it as a link farm on disposable hosting, suggesting a phishing or redirection scheme. Although no scripts were explicitly extracted, the PDF structure and heuristic firings point towards an attack pattern involving the exploitation of PDF vulnerabilities or social engineering to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://universitecentrale.net/uploads/FCK_files/file/wuwilidemitatetu.pdf In PDF document text
    • http://9275522-travel.com/userfiles/file/8317470727.pdfIn PDF document text
    • http://smolninskayahotel.com/userfiles/file/14498971831.pdfIn PDF document text
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614c45e7c43fd---69296972389.pdfIn PDF document text
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/16153c569c9625---54133634816.pdfIn PDF document text
    • http://imobilestore.de/userfiles/file/zizutevazerolezopedof.pdfIn PDF document text
    • https://leise.ru/admin/ckfinder/userfiles/files/98336888753.pdfIn PDF document text
    • https://al-farh-iq.com/upload/userfiles/file/95368082683.pdfIn PDF document text
    • http://0228339500.kad.tw/kads/ckfinder/userfiles/files/17087492993.pdfIn PDF document text
    • http://bradzo-ep.com/uploads/files/24124510176.pdfIn PDF document text
    • http://k-sta.kr/FileData/ckfinder/files/20210911_1661C8133BDA21D6.pdfIn PDF document text
    • https://euinsuti.ro/app/webroot/files/userfiles/files/24257670047.pdfIn PDF document text
    • https://nvsrolko.org/ckfinder/userfiles/files/jadefedunajalidid.pdfIn PDF document text
    • http://radio-salsa.com/php/rs/filesupload/file/47940689045.pdfIn PDF document text
    • https://pindimana.in/uploads/file/sezusidapezu.pdfIn PDF document text
    • https://gulamanis.com/contents/files/widejanegidezelo.pdfIn PDF document text
    • http://hongshengfish.com/uploadfiles/2021090711060123709.pdfIn PDF document text
    • http://tuvantindat.com/uploads/2021-09-02/images/files/kebelifiratukurujogoxado.pdfIn PDF document text
    • http://instit.ac/ckfinder/userfiles/files/buvobokulab.pdfIn PDF document text
    • https://vresponse.net/userfiles/file/vefelizaji.pdfIn PDF document text
    • http://afslab.asia/upload/files/41470567049.pdfIn PDF document text
    • http://www.jobibon.com/admin/userfiles/file/68788623847.pdfIn PDF document text
    • http://birkhoffhi.com/userfiles/files/sinomunote.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=indian+idol+contestants+nowPDF 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_off0000b42a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB42A 10300 bytes
SHA-256: 3811c7774b8e6340a50e511a1fd1d27c3ca4a1519884ed582572084bda7bc007
font_01_sfnt_off0000cb88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB88 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e39a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE39A 16948 bytes
SHA-256: f8ed05f52eaa31cd3aa28dc3a714d81a8a38e250613bb4719bd7d82db43bbe0f