Malicious PDF — malware analysis report

Static analysis result for SHA-256 91fd006bc3eb1541…

MALICIOUS

PDF

77.1 KB Created: 2021-09-07 16:04:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 346d62721067ad682d1e5048214d1e3a SHA-1: bbcf96c5246a8e8f28d82f064582cec916be18d2 SHA-256: 91fd006bc3eb15410b865c35a192abf01a84c35e92be538d74ae97f79cce26f7
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The document contains numerous links, many pointing to compromised WordPress sites, suggesting it functions as a link farm to distribute malicious content or phish for information. No scripts were extracted, but the structure and URL patterns strongly indicate a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/b8b90233ae45306eec1ebade4a8ca1b4/maziponilomuvo.pdf In PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c93db5bcd0---mitasew.pdfIn PDF document text
    • http://thegoshow.net/userfiles/file/bidoletumunojoj.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fa0025d1306---7916663064.pdfIn PDF document text
    • http://geopraxis.it/userfiles/files/malagitipewunonejam.pdfIn PDF document text
    • https://regenerativetherapyforpain.com/wp-content/plugins/super-forms/uploads/php/files/41e897a3250a2c447ab8c939ac7fe6f2/faxajabeduke.pdfIn PDF document text
    • https://tahitotfaluovodak.hu/ckfinder/userfiles/files/subiwobenu.pdfIn PDF document text
    • http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/1608853e48a320---69975186494.pdfIn PDF document text
    • http://srsheicha.com/uploadfile/file/kowenebunokaf.pdfIn PDF document text
    • https://tarzminder.com/resimler/files/banigesake.pdfIn PDF document text
    • http://asesoriazabalburu.org/azaba/files/file/vilajuzotu.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/lijisijo.pdfIn PDF document text
    • http://hatowo.com/app/webroot/uploads/files/68360310161.pdfIn PDF document text
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/8iv65d5bb93vj0l9v8tirhdkvs/11209529703.pdfIn PDF document text
    • https://digicpictures.com/downloads/patubujuxup.pdfIn PDF document text
    • http://stressmanagement-karriere.de/userfiles/file/45849318645.pdfIn PDF document text
    • https://www.3dreamchurch.com/wp-content/plugins/super-forms/uploads/php/files/6fa28467d8a1ea1210d78d077e6f1b6f/bifowi.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-5-22/20210522193339200108.pdfIn PDF document text
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/d5b0a38188ffcbd10af65d4e6b8fc38c/76966005329.pdfIn PDF document text
    • http://yuanjen.com/ckfinder/userfiles/files/63297240532.pdfIn PDF document text
    • https://urbanplace.me/wp-content/plugins/super-forms/uploads/php/files/dbdacc75742c5b57e017b99365853b9e/55678675743.pdfIn PDF document text
    • http://thetsaban3watnuea.com/UserFiles/file/sowavunagadigekunol.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=earth+day+worksheets+kindergartenPDF 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_off0000c98f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC98F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e1a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1A6 10756 bytes
SHA-256: 23cf90094dad0ba1f18a9c0b51d07d6b8dbc51041a1222709eb3ccb37339f17a
font_02_sfnt_off0000fa36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA36 17276 bytes
SHA-256: 5105eaf7443853feace9aec3044a6e3debdd5a8ed37034e1de52be989d7cf75f