Malicious PDF — malware analysis report

Static analysis result for SHA-256 8e4ab2efa71ec4b4…

MALICIOUS

PDF

68.5 KB Created: 2021-09-08 23:04:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: c9ff98f4a5452fe23e737940ba6d2c06 SHA-1: 188d0e35431ce349cb222b0fd422310befe723dd SHA-256: 8e4ab2efa71ec4b4d57b2a3431bc327060c5797690f0f44f259f81393c0b21b9
86 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF exhibits characteristics of maliciousness, including malformed streams and a high ML classifier score. It contains numerous embedded URLs, many pointing to disposable domains, suggesting a link farm or redirection mechanism. While no scripts were explicitly extracted, the PDF structure and heuristics indicate it's designed to exploit vulnerabilities or redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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://kantipursecurity.com/userfiles/file/wilurezelilubalepumugame.pdf In PDF document text
    • https://ever-progress.com/upload/files/ralokazafegawegar.pdfIn PDF document text
    • https://kolegium.inaheart.org/upload/files/41419290819.pdfIn PDF document text
    • http://glamour-nsk.ru/ckfinder/userfiles/files/sumafupijefukezigeruf.pdfIn PDF document text
    • http://elcwma.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/jufakid.pdfIn PDF document text
    • https://degardo.hollandpazsit.hu/ckfinder/userfiles/files/85098873660.pdfIn PDF document text
    • http://narcisse.sk/editor_uploads/files/31481373282.pdfIn PDF document text
    • http://sdds.be/userfiles/file/59127328903.pdfIn PDF document text
    • http://automyjka.pl/automyjka.pl/userfiles/file/buxenoxezupagatevodosa.pdfIn PDF document text
    • http://www.solarwindependence.com/ckfinder/userfiles/files/tevid.pdfIn PDF document text
    • http://szilasfood.hu/pic_upload/files/4127442431.pdfIn PDF document text
    • https://olympicwroclaw.pl/zdjecia/fck/file/tadukenukofibupepukav.pdfIn PDF document text
    • https://komunalno.vrgorac.hr/files/viviremefowadovasajeveru.pdfIn PDF document text
    • http://veterinariomauracotti.it/userfiles/files/51949915108.pdfIn PDF document text
    • http://www.globalnautique.nl/upload/files/gulidesatoxolidifulunov.pdfIn PDF document text
    • http://rosabaum.de/web/editor/files/37737992598.pdfIn PDF document text
    • http://yuanjen.com/ckfinder/userfiles/files/fageva.pdfIn PDF document text
    • http://opersan.com/file/71444704376.pdfIn PDF document text
    • http://balmybnb.com/t/tutorfirm/uploads/ck/files/kexowalemufe.pdfIn PDF document text
    • http://niktid.ru/userfiles/file/89332790922.pdfIn PDF document text
    • http://eptesteplelek.com/uploads/file/61879351415.pdfIn PDF document text
    • http://modelseafarm.com/kweb/ckfinder/userfiles/files/desarupofuxupavuwu.pdfIn PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161319f5388526---bironotobelopugozuneg.pdfIn PDF document text
    • https://wonwon.taipei/photo/file/difasenulotapilanan.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=dls+20+android+downloadPDF 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_off0000b161.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB161 10340 bytes
SHA-256: efcdc9092b0605b5f8b87a36f975cc534f9b03040ebdfd09b84b7fa39490d7b4
font_01_sfnt_off0000c8dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8DC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e0ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0EE 14176 bytes
SHA-256: d5a71ccaf28b6f4f703227a1e8c4ebcaf8d86b91fae068b74962097c8861dd60