Malicious PDF — malware analysis report

Static analysis result for SHA-256 67e22aa8105cad90…

MALICIOUS

PDF

79.0 KB Created: 2021-05-26 03:35:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 5d827501ca58517240ec38f381b865e0 SHA-1: 1940c442cff299742cb2aedd790377de9419a134 SHA-256: 67e22aa8105cad9075e9be44251d4f52d24fc86ec1f8d76b131f512872a3b350
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as 'Pdf.Phishing.Trojan' and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to compromised CMS upload storage and disposable hosting, suggesting an attempt to redirect users to malicious sites. The document body, though heavily obfuscated, contains metadata related to its creation by wkhtmltopdf, but no direct textual lure is discernible.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606f29597081d---81173421088.pdf In PDF document text
    • http://planetamama.ru/files/file/45736897188.pdfIn PDF document text
    • https://leo-translate.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1608d1e6891998---67508333633.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/6bec4551be54fe796139fbcf79329817/86702265358.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608534fd3599a---lozodexutazowitaduji.pdfIn PDF document text
    • https://www.movingwithmagna.com/wp-content/plugins/super-forms/uploads/php/files/9241300bbdee415df0c89bdd4e441d49/4963346650.pdfIn PDF document text
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f099c266a6---1353557468.pdfIn PDF document text
    • http://anhuicrew.com/upload_fck/file/2021-4-29/20210429024719735364.pdfIn PDF document text
    • https://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/b0943c1ae9ff89532229323a20685b78/71789978536.pdfIn PDF document text
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16098bd61067b0---46786317177.pdfIn PDF document text
    • http://big-blue-bus.com/pics/fotos/1/file/romawofufajimuxok.pdfIn PDF document text
    • http://scro.ru/pic/file/lejit.pdfIn PDF document text
    • http://iideree.org/wp-content/plugins/formcraft/file-upload/server/content/files/160901b746b1ee---28681154081.pdfIn PDF document text
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/0c471261806fb91b636be269458b6ca2/51470869524.pdfIn PDF document text
    • https://atx-stroy.ru/wp-content/plugins/super-forms/uploads/php/files/5408e3ac2731ea3912f304e15f43d48e/wuwabepurusalunetujunozi.pdfIn PDF document text
    • http://riskhedgetech.com/uploaded/file/67196558960aa74232b7b9.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=student+exploration+cladograms+gizmo+answersPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f43f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF43F 5708 bytes
SHA-256: b6f38f05b13550ff16ff26271aff4aa78c9525e8c8856654c68b136e955ac407
font_01_sfnt_off000107b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107B1 11640 bytes
SHA-256: 3c003329519620ba290ddf742b762286de78d3abb5fc6cc841b417e0a956bdb5