Malicious PDF — malware analysis report

Static analysis result for SHA-256 b39f5c389b5e1573…

MALICIOUS

PDF

84.2 KB Created: 2021-07-01 22:01:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: d9731727e9dc51c2c0ba19277d98d61a SHA-1: 6a8470184658310ea0ae0991b515064d04aeff03 SHA-256: b39f5c389b5e1573361140ddb41b96f73ab85e38f916991cca991261b677a866
216 Risk Score

Malware Insights

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

This PDF file is identified as malicious by ML classifiers and ClamAV, exhibiting characteristics of a phishing lure. It contains a link farm pointing to compromised WordPress upload directories, suggesting an attempt to distribute further malicious content. The presence of a 'Password-protected archive' lure indicates a common tactic to bypass gateway security by encrypting the payload until after initial inspection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) or Microsoft license-boilerplate documents that carry no urgency or charge/dispute escalation.
  • 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://queure.ru/uplcv?utm_term=if+i+told+you+that+i+love+you+would+you+tell+me+that+you+love+me+back PDF link annotation
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac1b27020d0---65603082535.pdfIn PDF document text
    • https://www.ideaklinik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bca021191e---koketiwukojoji.pdfIn PDF document text
    • https://www.movingwithmagna.com/wp-content/plugins/super-forms/uploads/php/files/1c52da7fbf5ddd48d9e19da213c3f33f/20552400962.pdfIn PDF document text
    • http://amy-tsai.com/images_express/userfiles/files/58211541218.pdfIn PDF document text
    • https://ivfnna.gr/wp-content/plugins/super-forms/uploads/php/files/67cd06f06cbc7817739772b4ad03e2d4/nabobetinebigap.pdfIn PDF document text
    • https://lerong.vn/wp-content/plugins/super-forms/uploads/php/files/0ba745c3d4eb5ad665e2c1c5e252bce0/maruf.pdfIn PDF document text
    • http://alimentosldm.com/userfiles/file/sarelolakiwojoxenib.pdfIn PDF document text
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/e049c29cfe69148750f135fd3a9b43f7/38276075102.pdfIn PDF document text
    • http://obrienbuilders.com/userfiles/file/gexigajolelamiwusitox.pdfIn PDF document text
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16084cf89cb783---wivipepimi.pdfIn PDF document text
    • http://hanhthien.net/uploads/file/tulasut.pdfIn PDF document text
    • http://spreewaldatelier.de/img/editor/file/vularetofexez.pdfIn PDF document text
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16083fe2dd63b5---ragat.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/ba3cfeecb4496f518ba43d7a96a10a33/pukadi.pdfIn PDF document text
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/fb0f73d8557c8949d3e61407f708e142/xewukakapobe.pdfIn PDF document text
    • http://alphasigmaoverseas.com/userfiles/file/sogozuduvafawiwofupapij.pdfIn PDF document text
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b37747313ed---tugixo.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/160852b7a7cc51---nujepirilujof.pdfIn PDF document text
    • https://sarujiovalente.com/wp-content/plugins/super-forms/uploads/php/files/jk20e1nu8c15ga130iop7mse3s/wugekagonumimamodupid.pdfIn PDF document text
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/8b314ec0d09534d5a34cbe6a298233b4/63610821469.pdfIn PDF document text
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077faba2d7de---sevuzifolal.pdfIn PDF document text
    • http://pamat.ro/UserFiles/file/rabufova.pdfIn PDF document text
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/16091206c79672---kixewadivetob.pdfIn PDF document text
    • https://bursakaynak.net/userfiles/file/limetosaburego.pdfIn PDF document text
    • http://opalsolar.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160796d513ba86---defesusogijoxujowa.pdfIn PDF document text
    • 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_off0000e3d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3D3 17468 bytes
SHA-256: 3ed7bec20ecf90b312f4fa70b1ab987751ee0aa69af88abc55a2a63bc57f36c9
font_01_sfnt_off0001111c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1111C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012933.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12933 10920 bytes
SHA-256: 52e16a4e9925e0baaa1fa56083b79fa1dd1d64ac84e238b361e13c1e611826ed