Malicious PDF — malware analysis report

Static analysis result for SHA-256 048196f016a4222f…

MALICIOUS

PDF

74.2 KB Created: 2021-09-08 09:19:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 339a381ddc132056e1c393a5daef8efa SHA-1: dd138c920e588faa36a3847d9a9821e063e2b6e6 SHA-256: 048196f016a4222fa4aff5b5580c101f95a59a53f7a6ecbc37126ac6bf3a9ee8
156 Risk Score

Malware Insights

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

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS upload storage and disposable hosting. The PDF document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's a container for these malicious links rather than user-readable content. The primary attack pattern involves directing users to external, potentially malicious websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://djhelaly.com/wp-content/plugins/super-forms/uploads/php/files/1c0c2074d52cf8ee8170ffcab3b3b059/wowubo.pdf In PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/655b97e1187ea3196d32c73e3e8d38c1/rivula.pdfIn PDF document text
    • http://sonsuadogo.org/Images_upload/files/56054672903.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a9e89a304a9---dinefomiki.pdfIn PDF document text
    • https://rjiminfra.com/wp-content/plugins/super-forms/uploads/php/files/f48ee8e6143fbde57dc4b4ab28cf5aef/7328284765.pdfIn PDF document text
    • http://raunlarose.us/wp-content/plugins/formcraft/file-upload/server/content/files/1608f9dbab6bbf---limogemom.pdfIn PDF document text
    • http://palestraarkadia.it/userfiles/files/wogibivoxaf.pdfIn PDF document text
    • http://mrybalko.ru/files/kexabasufofejazenixisezo.pdfIn PDF document text
    • http://floral-design-lindgens.de/userfiles/file/jejupiradoxafaxatusurikuk.pdfIn PDF document text
    • https://georgiamusicpartners.org/wp-content/plugins/super-forms/uploads/php/files/4e59ecc1381f9cecdf4e462dd6a357da/22080067824.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609db01364657---rulef.pdfIn PDF document text
    • http://amandatravel.com/userfiles/file/badeguzulodakiwasujuj.pdfIn PDF document text
    • http://tragiaocolamsapa.com/userfiles/image/file/78520768356.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/16087b41a4b4a1---15338057583.pdfIn PDF document text
    • https://yournew.site/wp-content/plugins/super-forms/uploads/php/files/piceopca5h0hm4aqku840nap2u/1589063603.pdfIn PDF document text
    • http://6nergy.fr/6nergy/sites/default/user/file/tamimonuzafebilavokab.pdfIn PDF document text
    • https://amiablediamonds.com/wp-content/plugins/super-forms/uploads/php/files/65d833ebd90dd44e16e26c2bbd888b44/fazusagobelimunogeji.pdfIn PDF document text
    • https://educationindiajournal.org/ckfinder/userfiles/files/1280833950.pdfIn PDF document text
    • http://jmestateplanning.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/bilijuxur.pdfIn PDF document text
    • https://nangluongvada.com/uploads/files/polefureni.pdfIn PDF document text
    • https://canvasations.com/wp-content/plugins/super-forms/uploads/php/files/73476b42eb9302ab9badd250c8831855/xifowisakenu.pdfIn PDF document text
    • http://erex.hu/upload/file/rurijubuwoxupuso.pdfIn PDF document text
    • http://phillipwhiting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb1d5c9e532---tibediliganad.pdfIn PDF document text
    • https://samiznojmo.cz/wp-content/plugins/super-forms/uploads/php/files/6b4d23aa4371c5aaaeab95bcd0ffc8c2/8065705315.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=shannon+wiener+diversity+index+pdfPDF 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_off0000c07d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC07D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d88f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD88F 16084 bytes
SHA-256: 4e893e36c3cc9401e79df46849e6280042ddaa06d536268c80c683a27b82f295
font_02_sfnt_off00010172.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10172 10992 bytes
SHA-256: aeec9df08cb6aead054824d1d1e6fdbd9e466ba8063176698b12589f358d1a68