Malicious PDF — malware analysis report

Static analysis result for SHA-256 e8fa771c683cccf4…

MALICIOUS

PDF

87.6 KB Created: 2021-07-31 01:59:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 66ccb8107bfd41d9d577cfc824567138 SHA-1: 8bec0b41af52eb2c65883db84e27fc2f3d00baf4 SHA-256: e8fa771c683cccf46b1495b56f119713f3120e2ac0849ea03e241b2ce36beae5
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, suggesting an attempt to redirect users to malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests the document's purpose is to act as a link farm, likely for malicious redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://lsneotek.com/ckupload/files/wunapo.pdf
    • http://wuxihemei.com/ckfinder/userfiles/files/20210719_023508.pdf
    • http://ewtch.com/upload/files/lusoviwaxagovijafipoko.pdf
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/0f60b2af896199c8127a5598e0f6e173/7160781752.pdf
    • https://refour.dk/wp-content/plugins/super-forms/uploads/php/files/4fb582223c67f01eb1b124da4f496d9a/72067096926.pdf
    • http://ganan10.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160cf2bced5f34---garudanapal.pdf
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/16079eedd3a968---99089276739.pdf
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/1609f1a47173cd---gagusalarozomumat.pdf
    • http://unseenadventure.com/userfiles/file/68525350492.pdf
    • http://tourbusan.net/FileData/ckfinder/files/20210706_FA578157F7563A4B.pdf
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9cb92a1b37---gifugedurizeruguk.pdf
    • https://attack.lt/images/files/porexosokimigixekavo.pdf
    • http://www.bluefashion.cz/ckfinder/userfiles/files/7956063593.pdf
    • http://deforma.it/userfiles/files/wuruv.pdf
    • http://lovesushiscv.com/uploads/files/zaretalezigimivuzu.pdf
    • http://adaviestransportltd.com/userfiles/file/23151122493.pdf
    • https://niboparis.com/upload/fckeditor/files/51812809560.pdf
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160a4d10163c7a---zuriro.pdf
    • https://hiampelectric.com/wp-content/plugins/super-forms/uploads/php/files/e3e70887d0a4052dfb07d1b65e1fd09e/nirinepole.pdf
    • https://aftaplan.com/works/peepsparty/html/upload_files/file/70967385881.pdf
    • https://noddy.nu/images/file/datenadigitapezexaxa.pdf
    • https://tkquiz.com/userfiles/file/nurejoratezupiropus.pdf
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/pg407tbnnjd0mnlmd77m0eqrri/suwedagivefudajalenowif.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=how+sensitive+is+a+sainsburys+pregnancy+test
    • 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_off0000f4b2.bin
9a53503171be76f20f8c1a9753d494034081cb489eb694db12380eefa5a7f53d
pdf-font-stream PDF embedded font (sfnt) at offset 0xF4B2 16304 bytes
font_01_sfnt_off00011ee6.bin
f57b73b1cc70b8c36157420f327f60135e507ef49028876ca1f45ab08c3ec47e
pdf-font-stream PDF embedded font (sfnt) at offset 0x11EE6 11000 bytes
font_02_sfnt_off0001387f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1387F 16792 bytes