Malicious PDF — malware analysis report

Static analysis result for SHA-256 f85d674136711692…

MALICIOUS

PDF

70.8 KB Created: 2021-09-24 15:30:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: ee12178d17687c4bdb132dd190050734 SHA-1: 3987da5c0628f5c58ab484f2da2da9592150c6bd SHA-256: f85d6741367116922b02a8571b1475e1ce02f71d5d6943c7a0fd85dc32cd2088
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. The PDF contains numerous embedded URLs, many pointing to disposable domains, and one heuristic specifically flagged it as a link farm designed to obscure the final destination, which is presented as a firmware download. While no scripts were directly extracted, the PDF structure and the nature of the URLs suggest an attempt to deliver a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://okgwa.net/50/files1/file/josiwakixevi.pdf In PDF document text
    • https://rowadalbyt.com/userfiles/files/nimesemuluzogazovil.pdfIn PDF document text
    • http://kovove-ploty-brany-zabradli.cz/UserFiles/File/guzejufod.pdfIn PDF document text
    • http://asvpp.fr/pdf/wowam.pdfIn PDF document text
    • https://baptistfriends.org/media/tigalerizepodozapa.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613f1aae62374---71718184235.pdfIn PDF document text
    • http://americandeliorder.com/uploads/files/64143116211.pdfIn PDF document text
    • https://invision.buzyhub.com/files/nivapinuzuxab.pdfIn PDF document text
    • http://artechq8.com/beta/uploads/files/38343500691.pdfIn PDF document text
    • http://synergytaekwondo.com/click2buy_newp/userfiles/file/wodogolojoluzobafizote.pdfIn PDF document text
    • http://lyshiying.com/d/files/39788016668.pdfIn PDF document text
    • http://topnotchimports.com/ckfinder/userfiles/files/samirukabo.pdfIn PDF document text
    • http://www.swaving-stalinrichting.nl/ckfinder/userfiles/files/14819538852.pdfIn PDF document text
    • http://soepcentrale-dekeyser.be/userfiles/file/dadikutuwematazuves.pdfIn PDF document text
    • http://poorclarescork.ie/images/mosorer.pdfIn PDF document text
    • http://millecolori.it/images/file/83750400448.pdfIn PDF document text
    • https://mediaget.ru/userfiles/files/wonon.pdfIn PDF document text
    • http://mottaing.eu/userfiles/files/73922718316.pdfIn PDF document text
    • https://kirbas.com/img/uploaded/file/74463616156.pdfIn PDF document text
    • http://seamcc.com/UserFiles/files/37498929012.pdfIn PDF document text
    • https://goacetours.com/ckfinder/userfiles/files/66678505507.pdfIn PDF document text
    • http://longthinhphat.net/uploads/files/kexikijibesed.pdfIn PDF document text
    • https://regiefranchet.fr/userfiles/files/95070523074.pdfIn PDF document text
    • http://www.pilatesyoga.hr/files/files/35444738748.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=i9300+firmware+4.1+2+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_off0000b247.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB247 15688 bytes
SHA-256: f7dbab3ca731eb1f745bfb6df03bb56f0f3aaa9c8448820c0f0411812a90021c
font_01_sfnt_off0000db02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB02 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f319.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF319 11064 bytes
SHA-256: c54192c1b083f920c7db349cfc6c472f6ddec4b846450c22f02157250549a9a8