Malicious PDF — malware analysis report

Static analysis result for SHA-256 aab3f99c9671a15f…

MALICIOUS

PDF

68.8 KB Created: 2021-09-25 01:06:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3b825759e8672c9672b6998d3a3c8afc SHA-1: ccc7304dfb5d286eeefd1faea9580840260f501e SHA-256: aab3f99c9671a15f07ae5018202b0a5930247c294f174d12a7557501b4c87623
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF employs an image-only lure, a common tactic for phishing or malware distribution, as indicated by the PDF_IMAGE_LURE heuristic. It contains numerous external URIs hosted on disposable domains, suggesting a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely involving the execution of embedded JavaScript to download a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 1 image(s), only 0 text block(s), carries a click-outward action, and is only 68 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • 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://coretry.ru/uplcv?utm_term=rurouni+kenshin+live+action+movie+full+english+sub+free
    • https://tourgardan.com/basefile/tourgardancom/files/41657490270.pdf
    • http://sherwoodchambergolf.org/ckfinder/userfiles/files/nuwora.pdf
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/1613f51654611e---64309126340.pdf
    • https://paardenwelzijnscheck.nl/app/webroot/files/ckeditor_files/files/78947940696.pdf
    • https://esterkins.de/ckfinder/userfiles/files/notidorupudode.pdf
    • http://savalis.ru/userfiles/file/76783926660.pdf
    • https://adtw1.com/ckfinder/userfiles/files/57761928669.pdf
    • http://globalsocialwlefaresummit.com/app/webroot/uploads/ckuploads/files/79836114184.pdf
    • http://datev.hu/ckfinder/userfiles/files/66142534750.pdf
    • http://morebricks.com/ckfinder/userfiles/files/jigojokibavebidirimivere.pdf
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16148004da4604---tepabatolikipabivepa.pdf
    • http://lso-msm.fr/userfiles/file/2357235971.pdf
    • http://mitroc.com/userfiles/file/43814293438.pdf
    • http://firmykominkowe.pl/Obrazki/edytor/file/mixosezewix.pdf
    • https://apoiotelecom.com/imagens/img_fckeditor/file/55553472000.pdf
    • https://www.poole.ed.jp/system/ckfinder/userfiles/files/wipamikisodimenujigoko.pdf
    • https://anmimar.com/royal/userfiles/file/naruraxek.pdf
    • http://cesvil.it/filesUploads/file/tabefewi.pdf
    • http://jfhcoaching.com/userfiles/files/sebeziguvuxubaxiv.pdf
    • http://turksebruiloften.nl/userfiles/file/70860439760.pdf
    • https://www.greenlakecruises.com/ckfinder/userfiles/files/74596641699.pdf
    • https://termokingbt.com/ckfinder/userfiles/files/sovuxivifo.pdf
    • http://dongphat.net/upload/files/misomukanerorixanixek.pdf
    • 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_off0000b067.bin
cf6a987842b1180fca061ec3356d4121fdf69c0975913f3390db9c7ccce4d413		 pdf-font-stream PDF embedded font (sfnt) at offset 0xB067 13924 bytes
font_01_sfnt_off0000d314.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1		 pdf-font-stream PDF embedded font (sfnt) at offset 0xD314 16792 bytes
font_02_sfnt_off0000eb2b.bin
0e8970f64bf61cfe75b33254bef484d7a5ea33b900071c8d459fc9793f3d6a11		 pdf-font-stream PDF embedded font (sfnt) at offset 0xEB2B 11224 bytes

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