Malicious PDF — malware analysis report

Static analysis result for SHA-256 18aa63a644420c9b…

MALICIOUS

PDF

118.7 KB Created: 2021-09-07 18:01:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: cb9792f55a2272fc88dd71f32bf0dd82 SHA-1: 74466b5e9f6a9bc46b122b93db940fb5a8596e01 SHA-256: 18aa63a644420c9be7ed6427510e6c4bf3683a582bfc04b11baa021a81b0367c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Static analysis revealed it functions as a link farm, with numerous embedded URLs pointing to various websites, including those hosted on compromised CMS uploads. The document body is unreadable, but the heuristic firings strongly indicate a phishing or redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

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://robwalker.net/fckupload/file/nabupiwikule.pdf In PDF document text
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16082ba9b2eac5---vitorupodezutida.pdfIn PDF document text
    • https://alshamiltrading.com/alshamilfiles/file/45384399634.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608fbfa18d1e9---weretetavatubezakeze.pdfIn PDF document text
    • https://xn--fct8ml6mwue.tw/uploads/files/6177918610.pdfIn PDF document text
    • http://scamps.biz/userfiles/file/7670095143.pdfIn PDF document text
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608000c0d8a0e---19065408025.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086d5048b55d---teremipogi.pdfIn PDF document text
    • https://limsurdua.com/contents/files/43967583037.pdfIn PDF document text
    • https://awlights.com/wp-content/plugins/super-forms/uploads/php/files/35dd2f0212c967df9cf8f9ec5efc98cd/50399405638.pdfIn PDF document text
    • http://uekekb.ru/!upload/files/24964265937.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/160753b2667730---wirubitozumijij.pdfIn PDF document text
    • http://hilltopperalumni.com/clients/9/93/936f23dc4abb03f6d4a1aae2c8a32781/File/50690486124.pdfIn PDF document text
    • http://plastikacz.cz/soubory/files/kevukisojixalorolu.pdfIn PDF document text
    • http://fine-cottage.ru/userfiles/files/farolik.pdfIn PDF document text
    • http://www.makattakasinti.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071f039c11a5---34182487746.pdfIn PDF document text
    • https://villamishkan.com/310renonew/front/images/files/36838291288.pdfIn PDF document text
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b83d9a5f475---3314135195.pdfIn PDF document text
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/0se3775vo14f0h6255uts3um01/42753506341.pdfIn PDF document text
    • http://sochistandart.com/ckfinder/userfiles/files/71929032790.pdfIn PDF document text
    • http://yuanjen.com/ckfinder/userfiles/files/vuximorifanabokogemutol.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=radionette+solist+rnshdiw15e+manualPDF 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_off000165ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x165CE 20640 bytes
SHA-256: fc0b55be0873476321f7d64750555e65d5c4fe758c3886dee9a58dae81c7e468
font_01_sfnt_off00019bd2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19BD2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001b3e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B3E9 10928 bytes
SHA-256: fc091e8296c0daf6dc595416be4eda99beba2a30ce269e6fa05f97fa3373acbb