Malicious PDF — malware analysis report

Static analysis result for SHA-256 b557e654db39e58e…

MALICIOUS

PDF

94.8 KB Created: 2021-07-30 15:27:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: a88b776ff359eb9e9ebf721cb4ef54a7 SHA-1: 3f70151c19fc916a4900ea33258f781b068db12b SHA-256: b557e654db39e58edd2bff4a7a279efafe6a7d379c2ba5d36f33cf3464db57c1
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many of which point to compromised WordPress sites and other disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or to serve further malicious content. The document body is unreadable, but the heuristic firings and URL analysis are sufficient to determine its nature as a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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 http://camionespanamericana.com/userfiles/file/80022657905.pdf In PDF document text
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/rurqq2gehfup57g034j8jhhim4/rotavuso.pdfIn PDF document text
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160a6e77b5c45f---37899071573.pdfIn PDF document text
    • https://europartner2.pl/uploads/85486459475.pdfIn PDF document text
    • http://beckydavidsonhomes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160eddd2780f6a---92484978914.pdfIn PDF document text
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/1606d542e675db---39330707815.pdfIn PDF document text
    • http://koreaseowon.com/ckupload/files/11541168745.pdfIn PDF document text
    • https://burkina-businessschool.com/business_school/uploads/file/nekowano.pdfIn PDF document text
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/208a0ab7bfdc12e9a2cabf0b7ba4f7d0/tagerufegaximinonetixo.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/d8567d6f9b483435b4386c15e4016f04/juvovedovilopodu.pdfIn PDF document text
    • http://asfus.net/virgsurv/userfiles/file/mavijazozixuwoful.pdfIn PDF document text
    • http://air-con.ru/upload/files/jatalelolebawigixexug.pdfIn PDF document text
    • https://hopefor.today/wp-content/plugins/super-forms/uploads/php/files/dba9ca1642c7ae6b10efc98cf0699ca9/72040047437.pdfIn PDF document text
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/b67bfa452e9b882e1f3652e45721d349/76447187619.pdfIn PDF document text
    • http://evohome.pl/userfiles/file/zazovurikoboworuj.pdfIn PDF document text
    • http://dansecyr.ca/pdf/file/5550184862.pdfIn PDF document text
    • http://magooferta.pl/uploads/fck/file/47554287763.pdfIn PDF document text
    • https://sinarwaja.com/account/files/nusikerukusa.pdfIn PDF document text
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608cf732e4d95---baloburikusanota.pdfIn PDF document text
    • http://cuatro-pr.org/sites/default/files/file/26357238144.pdfIn PDF document text
    • http://pvsystexperts.com/wp-content/plugins/super-forms/uploads/php/files/e55u4ngh8pgtaaofo0a8obuui6/vajoxudumimajisemajiwoze.pdfIn PDF document text
    • https://hotel-la-licorne.fr/userfiles/file/danoluxikigozof.pdfIn PDF document text
    • https://nvsrolko.org/ckfinder/userfiles/files/makifobimenelozojomugolu.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/dekulbaufffbc5digql6av3r24/lujosututeja.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160b98edc4dd06---38547414774.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=the+new+encyclopedia+of+modern+bodybuilding+workoutsPDF 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_off000109d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109D4 11564 bytes
SHA-256: 81c49ad58e55b4eb6774b1260ec98dd56e04096da5edf6e6920900e4bd58d7c4
font_01_sfnt_off000124b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124B1 18060 bytes
SHA-256: 8b16e4e961bbbc6fc60c3f949c99eefb028c2121aa7a04ffa5cc125c4ad79203
font_02_sfnt_off0001548a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1548A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1