Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5ec3b2fac25fe9b…

MALICIOUS

PDF

85.7 KB Created: 2021-09-10 15:41:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bc4e30d2986d11b35f93c888730431c5 SHA-1: 6a1e7d9dd2bca037b9994f7681f4d70ae9400ba2 SHA-256: f5ec3b2fac25fe9b18e66c339890a5f3f3890433893dc660fce70e19729a28ec
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external links, 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 numerous embedded URLs point towards an attack pattern involving directing users to potentially harmful external sites.

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 http://cleversystems.ru/userfiles/file/xonixefe.pdf
    • http://grasslandtj.com/upload/files/71346605810.pdf
    • http://energcomb.net/cms_enercomb/sgi_userfiles/userfiles/files/45703945966.pdf
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/42e882efdca4a081e4d0ad04036af758/9974907355.pdf
    • http://lesmashclub.com/imgUpload/files/4378972052.pdf
    • http://biogenetec.tw/image/files/20210909_195537.pdf
    • http://metalzilemboeventi.com/userfiles/files/mefaw.pdf
    • https://samavetpharm.com/userfiles/files/74406538092.pdf
    • https://barcelonamedicalcenter.com/files/galeria/files/ruviguduwo.pdf
    • http://kreativitaet-stadlhofer.at/global/images/userfiles/file/40888003700.pdf
    • http://mcrlclient.gilcom.ro/ckfinder/userfiles/files/dezosuzisifazum.pdf
    • http://esipro.be/userfiles/file/futopuwinopim.pdf
    • http://ipost.mn/ckfinder/userfiles/files/lumofunemabudavoku.pdf
    • https://dp-engineers.com/admin/userfiles/file/7899776207.pdf
    • https://stonebuild.bg/f/uploads/files/29689148497.pdf
    • http://omeofest.eu/userfiles/files/5957597200.pdf
    • http://specimport.by/files/files/kemuwijexidofaxaraxof.pdf
    • http://newkontakt.ru/userfiles/images/file/59401168562.pdf
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/161367577a7199---9116532725.pdf
    • http://brucemayrockinstitute.com/assets/ckfinder/core/connector/php/uploads/files/potisibafaf.pdf
    • http://imhome-listings.com/userfiles/files/soviwep.pdf
    • http://apsons.eu/files/file/89271234380.pdf
    • https://www.icicle-mountaineering.ltd.uk/ckfinder/userfiles/files/fututar.pdf
    • http://ingegnasrl.com/userfiles/files/81284470713.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=ideas+for+a+minecraft+world
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e9f3.bin
38002f042c7b6f6242b22329155dfb9f49abd0e37a0622a6d4e2e4d381631d17
pdf-font-stream PDF embedded font (sfnt) at offset 0xE9F3 17688 bytes
font_01_sfnt_off0001183a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1183A 16792 bytes
font_02_sfnt_off00013051.bin
502168105d34bf0149973d38be7d2ae3b7c616a4ecae92427728e582c8a08f9c
pdf-font-stream PDF embedded font (sfnt) at offset 0x13051 10672 bytes