Malicious PDF — malware analysis report

Static analysis result for SHA-256 2c99dba53731e318…

MALICIOUS

PDF

84.6 KB Created: 2021-07-31 17:48:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: e1fbc75ea3ac7e829821bc5d6145e62f SHA-1: 6032c3428303ce525041b21182771d8b82b8826a SHA-256: 2c99dba53731e318d5d01a0915d3adb747cbc2ed9d1d80cd628c6c78d309c5ee
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to websites hosted on compromised CMS platforms and disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the link farm heuristics and URL analysis.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://twinslock.com/ckfinder/userfiles/files/faboxan.pdf In PDF document text
    • https://1877painters.com/FCKeditor/file/28822778937.pdfIn PDF document text
    • http://abpaluso.com/upload/file/gubike.pdfIn PDF document text
    • http://www.gunyagder.org.tr/wp-content/plugins/super-forms/uploads/php/files/3c4a9im0h31gf4nmam0bm81ns5/90266715922.pdfIn PDF document text
    • https://aristonails.com/articles_files/files/zuvasiwopekotedovejozi.pdfIn PDF document text
    • http://grupomarsamo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8719530a60---zetikopedi.pdfIn PDF document text
    • http://aokisuper.com/ckfinder/userfiles/files/62884257309.pdfIn PDF document text
    • http://moto-bike.pl/userfiles/file/69593710520.pdfIn PDF document text
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071df4a8e8f8---nukibepez.pdfIn PDF document text
    • https://elitestrategyglobal.com/wp-content/plugins/super-forms/uploads/php/files/282ee071b4f91c2387effb493b0945e7/vidomovibamemabogod.pdfIn PDF document text
    • http://myjobcareer.net/userfiles/file/2021062900301373499.pdfIn PDF document text
    • http://mmckno2010.zkosuchdol.info/files/bubojalovofov.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160cacc6feacf1---goribelezapifewuzu.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160de48feb0a33---20485756892.pdfIn PDF document text
    • http://chiaranannini.com/userfiles/files/37397010202.pdfIn PDF document text
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/7toebalqj04vh6sc63jrnbtu27/5933905639.pdfIn PDF document text
    • https://gea99.com/ckfinder/userfiles/files/sekevupexuxo.pdfIn PDF document text
    • https://dispomydeal.com/wp-content/plugins/super-forms/uploads/php/files/e8a1df2c12ba6a9c01a5ca41f27fcec0/30998079240.pdfIn PDF document text
    • http://phdpecs.hu/userfiles/files/76096382727.pdfIn PDF document text
    • http://chnli.tw/CKEdit/upload/files/95559291817.pdfIn PDF document text
    • http://robalton.es/Albums/images/file///12931327607.pdfIn PDF document text
    • http://hnc2.com/userfiles/file/9829848435.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=reflexive+pronouns+quiz+pdfPDF 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_off0000e334.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE334 18176 bytes
SHA-256: a83f9afec068ee7e33dd8ef27aa62bcf0193f0feae0646a001f903f7ff1294e9
font_01_sfnt_off00011376.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11376 10752 bytes
SHA-256: be12c3b4df63330e6857c90ef008e01e74f5edf74d5596c5c8135ea5d144a4b6
font_02_sfnt_off00012c1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C1F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1