Malicious PDF — malware analysis report

Static analysis result for SHA-256 91f1f9f5bf4afcb2…

MALICIOUS

PDF

68.2 KB Created: 2021-10-03 02:07:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 20a3457ac9205f42882e81da60b1ce1a SHA-1: 72f81ccbb51559ca24f7b3a295a5b5549cb1c57c SHA-256: 91f1f9f5bf4afcb2e95fb1f8e8cc14725539087742640eb6c4a83d0c636bb5f6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external links, many of which point to compromised websites or disposable hosting, indicating a link farm designed to lead users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of techniques used to lure users into clicking malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://alkathirilaw.com/userfiles/files/46862708520.pdf In PDF document text
    • https://goodline.by/userfiles/file/97057313846.pdfIn PDF document text
    • http://rund-sro.cz/UserFiles/File/29086976479.pdfIn PDF document text
    • http://idrogastermoclima.it/Utentifile/FCKPage/file/defejoripemaberiwefoximof.pdfIn PDF document text
    • https://dnmpaint.com/sdcc/images/file/kivexegotiwozu.pdfIn PDF document text
    • http://portaldeaquidauana.com.br/ckfinder/userfiles/files/supefizedobo.pdfIn PDF document text
    • http://businessvaluationapp.com/fck_files/file/darudi.pdfIn PDF document text
    • http://lalicorne-hotel.com/userfiles/file/tofujupowix.pdfIn PDF document text
    • http://gimhaejazz.com/fckeditor/userfiles/image/wikexolusimigakerul.pdfIn PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132ee79eb882---8741713895.pdfIn PDF document text
    • http://mail.me.ntou.edu.tw/ckfinder/userfiles/files/20210909_072059.pdfIn PDF document text
    • https://ist-lb1.istanajp.com/contents/files/66425554776.pdfIn PDF document text
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/0c420ddeca5646eee3ed8a8059cb42e5/36130596912.pdfIn PDF document text
    • https://clubelsendero.com/img_pag/file/76200717510.pdfIn PDF document text
    • http://badaranquehablar.com/userfiles/files/38318667377.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140be2ea9ddf---kizizor.pdfIn PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/93b0fd3805c39ca6cd7435af08fe7fbc/90005919599.pdfIn PDF document text
    • http://wolfroccatiassociati.it/userfiles/files/94579855630.pdfIn PDF document text
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/c3e43868cd21e42e386035c12027bb30/zofabatanakafimo.pdfIn PDF document text
    • http://mygiftltd.com/userfiles/file/saworitotijuda.pdfIn PDF document text
    • http://digjamaica.com/app/webroot/files/zosilijebo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=use+of+znPDF 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_off0000af79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF79 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c78f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC78F 9776 bytes
SHA-256: f3dd5430227b7225a572385aaef39aea12264ee641fb9968e08977184439cfea
font_02_sfnt_off0000dd20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD20 15304 bytes
SHA-256: 9b1b79dde31f7f86d07ae35c5c0696bb15f95c399b20bbb7e72503efffbbb920