Malicious PDF — malware analysis report

Static analysis result for SHA-256 87384ed61df51a53…

MALICIOUS

PDF

80.9 KB Created: 2021-07-20 20:27:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9277990e081f80daeca38e5a57cb2927 SHA-1: e8255b8b9b722e38e5bee636637d307e1627e407 SHA-256: 87384ed61df51a5341d265e3e5ce16f4b2091f3ba71b4bc1ec8d87cc10c51813
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, pointing to numerous compromised WordPress sites hosting further PDF files. This suggests a phishing or malware distribution campaign leveraging these compromised hosts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608480a1eb955---4812251190.pdf
    • https://youstore21.com/wp-content/plugins/super-forms/uploads/php/files/183b9bce276209cd1c60d5c62b9dd26f/pobafelefuloxiroxaliwa.pdf
    • http://faradbox.pl/files/file/71790046016.pdf
    • http://tanphatinst.com/vietkiendo/upload/file/mifamalazuwi.pdf
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ba4e6245815---wufitebimekimowozoki.pdf
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160f3e845057e9---2023987857.pdf
    • https://cspdental.com/wp-content/plugins/super-forms/uploads/php/files/c3c42e67d474a4eef0aa925e8032216d/92594348775.pdf
    • http://zamokugrofa.sk/admin/fckeditor/file/gimarele.pdf
    • http://akkoryazilim.com/userfiles/file/kopemefum.pdf
    • https://creativenursery.net/home/creative/public_html/ckfinder/userfiles/files/wusubimijuxuloso.pdf
    • http://veitali.com/upload/files/febarerir.pdf
    • http://ailizia.com/userfiles/65348096463.pdf
    • http://yogo110.com/userfiles/file/zofemonilitubifalegamoxog.pdf
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/160751e63eca82---95905017833.pdf
    • https://www.skyline-recruiting.com/wp-content/plugins/super-forms/uploads/php/files/6e41e9f2c5bfac10ff50e8a22b32edc4/74026806788.pdf
    • https://ladychief.com/wp-content/plugins/super-forms/uploads/php/files/da9b9fe37d8195abfe6582421d4273bf/wejodovigufimiwel.pdf
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607fa8447dfec---44894723391.pdf
    • https://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/42c417f52dc10fa8700a96747d860e2b/sejeworibo.pdf
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075f6db70553---dipemowarureri.pdf
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/424efef4b4e408b4e9d58c1ba94bc868/sasuzagilujepejavo.pdf
    • http://iqlacpro.vn/emotive/upload/files/wodonironamali.pdf
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607dd1176a82d---54008452473.pdf
    • http://valaptop.com/ImagesVA/file/jitakuxeporesuwufawuvor.pdf
    • http://wamer.org/userfiles/file/juxojijetawimadevijupa.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=applause+for+you
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d7d5.bin
8f9ea729ff0a58d52b785913e72bbc5f38a8aac7987d3edbafee5b1cc4b6e951
pdf-font-stream PDF embedded font (sfnt) at offset 0xD7D5 10252 bytes
font_01_sfnt_off0000ef1c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF1C 16792 bytes
font_02_sfnt_off0001072e.bin
d4bd5aee1ee248aaf258ad6f15d29ef407472c70fefeaad0994245cbb5b174b6
pdf-font-stream PDF embedded font (sfnt) at offset 0x1072E 17172 bytes