Malicious PDF — malware analysis report

Static analysis result for SHA-256 bffc791b13e7a677…

MALICIOUS

PDF

84.8 KB Created: 2021-07-17 20:51:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 47782ee1d39f907d0db86d5584457fd6 SHA-1: 37b953b7c07fc0e1e6c94af8649ce30f247c9cb9 SHA-256: bffc791b13e7a67759a782ff11d7662f56820872b35fe92e0e31d285722b3d83
156 Risk Score

Malware Insights

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

This PDF file was flagged by ClamAV as a phishing trojan and by an ML classifier as malicious. It contains numerous links, many pointing to compromised WordPress upload directories, suggesting a link farm or phishing lure. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, lacking direct user-readable content but containing embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 https://okud-istra.hr/userfiles/file/92859404060.pdf In PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160803098415ab---nijubegusivutunotutol.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160830d358e91f---giwemoninaxuju.pdfIn PDF document text
    • https://massagetheory.ca/wp-content/plugins/super-forms/uploads/php/files/6edbc3341cd07cd42f102f388b54f826/4111995696.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad8ca61b8d2---42284127002.pdfIn PDF document text
    • https://carea2plus.com/wp-content/plugins/super-forms/uploads/php/files/55e5e7d81e28e6c182cb70783c07cff5/9671252620.pdfIn PDF document text
    • http://delawaretravelmedicine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dd3c0a82c0---papoteribufamis.pdfIn PDF document text
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/6fa547faf504c4a35309ccc976baaae6/xupofarevepi.pdfIn PDF document text
    • http://richmore.kr/uploadfile/fckeditor/file/kutepopabejamidenujozu.pdfIn PDF document text
    • http://techbis.pl/files/file/lumemegasoj.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cf66d98ad0c---65056403499.pdfIn PDF document text
    • http://www.dr.schure.net/ckfinder/userfiles/files/moreg.pdfIn PDF document text
    • https://menu2uplus.com/images/file/mivave.pdfIn PDF document text
    • https://floorco.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/a3326fe81bcccc3658d0595231455716/8229422321.pdfIn PDF document text
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc770a90c59---gavove.pdfIn PDF document text
    • https://fieldofgreen.com/wp-content/plugins/super-forms/uploads/php/files/1f4fddaf89d6d01cfe893f51d6dabf25/10334128289.pdfIn PDF document text
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607c4357cb8df---guxije.pdfIn PDF document text
    • http://brilsports.ro/userfiles/file///93556164794.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16090480f89036---4623528336.pdfIn PDF document text
    • https://penzionradvanice.cz/res/file/33147996537.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160acf997c3698---14417346637.pdfIn PDF document text
    • https://charteriraq.ir/basefile/charteriraqir/files/motepiduk.pdfIn PDF document text
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cd9f60d1cc---dasubasalaza.pdfIn PDF document text
    • https://jclifeschools.org/wp-content/plugins/super-forms/uploads/php/files/c9de4042a5366c4710082512cde09ddd/gujofabedi.pdfIn PDF document text
    • https://mrmobilewebsite.agency/wp-content/plugins/super-forms/uploads/php/files/5623e9471cb9b2a45713debda4ba3de9/44115070155.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=how+heavy+was+the+crossPDF 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_off0000ea4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA4E 10344 bytes
SHA-256: 7ff926cf394e63701e525063217bf6dc2d13676d0eff365abab63a6d1f7052a5
font_01_sfnt_off000101e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101E4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000119f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119F6 16928 bytes
SHA-256: d22a6928f3e6f5fb4e77d5d54154c28fca2bbacbddb2f074e7f6504a70032ec9