Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a797733cbdd7f22…

MALICIOUS

PDF

83.9 KB Created: 2021-09-03 17:20:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 48796e1d07f88cfb42ccb58ea18fa204 SHA-1: e8b6d6fd0bca1b5fd3d557dccf28da6888887800 SHA-256: 3a797733cbdd7f22de3f3de9744126a26f9aae8ecb93677ccecc8412de6e6ec9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users to malicious content. The document body is unreadable, but the heuristic firings strongly suggest a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://hzbmsj.net/images/upload/File/40442160650.pdf
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/f087d7519493d6986b54d2242c237198/bamibawejavanulesufatin.pdf
    • http://agisma.ru/files/pages/files/14406711596.pdf
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/161030b4b1c6f9---xokepetajezafo.pdf
    • https://ehotelgateway.com/bot/ckfinder/uf/files/7336281253.pdf
    • https://amiablediamonds.com/wp-content/plugins/super-forms/uploads/php/files/aede6a762dc04b963173ab79ddba38a5/dezubegamas.pdf
    • http://trongtinpc.com/luutru/files/43150941414.pdf
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/bb4288c551588469b55594ddaff6f7c9/sizenadita.pdf
    • https://ecoolteh.eu/galeria/file/92595462925.pdf
    • http://hotelclinton.it/userfiles/files/30430362630.pdf
    • https://barcelonacentromedico.es/files/galeria/files/tomatepu.pdf
    • http://benthanhsgfarm.net/images/uploads/files/41416679132.pdf
    • http://clair-environnement.eu/catalogue_dynamique/file/6885318746.pdf
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/0dddc74d08cdfdec008d7243734c60ae/vinovos.pdf
    • http://lifecare4all.com/upload/files/gubejigakudunizufewaminov.pdf
    • http://amongelite.com/ci/userfiles/files/27792526800.pdf
    • http://madmojo.com/fckupload/file/vesumegoriregupemilowax.pdf
    • https://autoschiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/160acf0c9089a8---tutepodapaxovusiwuw.pdf
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/er5r3gebvjmbc2t8o34milqhnj/wojigobewulejufe.pdf
    • https://cleartunemonitors.com/ckfinder/userfiles/files/kogifomi.pdf
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/dpn61d2ge44hiaoourmncqe0re/taxevumiludiluto.pdf
    • http://teaandtiarasottawa.org/clients/e/e8/e8f54e69a7463df9fd0adff13cd8e90f/File/rutuwebumiw.pdf
    • http://hotelclinton.it/userfiles/files/zizizirudizebeweborazi.pdf
    • http://livestreaming.group/wp-content/plugins/super-forms/uploads/php/files/8frs5gfjqt5ruo3k7na51rr8v6eub05l/zatasevar.pdf
    • https://alismobile.co.uk/wp-content/plugins/super-forms/uploads/php/files/a5c9adbad27f21948f1c372bd3044591/letisodakix.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=s.t.r.o.k.e+assessment+pdf
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c547da87108---limuxizulotire.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_off0000e063.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE063 16792 bytes
font_01_sfnt_off0000f87a.bin
9c3b1a9fa30bab1c1432576d85b14739a93223684e57dc9aabc118f1cde979f4
pdf-font-stream PDF embedded font (sfnt) at offset 0xF87A 10756 bytes
font_02_sfnt_off00011139.bin
b9fc2c5756a0c85b4879846a3792db589e9bdedb90e89e37b9869714220e6733
pdf-font-stream PDF embedded font (sfnt) at offset 0x11139 18940 bytes