Malicious PDF — malware analysis report

Static analysis result for SHA-256 8435f9371a2cc5ef…

MALICIOUS

PDF

70.9 KB Created: 2021-09-26 16:23:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 5ef670d7fa9035d78cd874d6d77fbf89 SHA-1: 396d220f360040da7830080a7ec131082e37583a SHA-256: 8435f9371a2cc5ef8cf09829b2bc624b4186281dbdfd23a3d657f744f8653541
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites and disposable domains, suggesting it functions as a link farm. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware delivery. The presence of multiple external URIs and link farm heuristics supports the classification as a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://garglob.ru/uplcv?utm_term=can+you+screen+mirror+to+a+chromecast PDF link annotation
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d008a90ff1---63163049684.pdfIn PDF document text
    • http://calisnt.com/uploads/files/sebuwozomafi.pdfIn PDF document text
    • http://educaholistica.com/resources/img/imagesck/files/xuwofiwekuzafuvekiwup.pdfIn PDF document text
    • http://uniontsg96.ru/admin/ckfinder/userfiles/files/febamofokutegakexowilu.pdfIn PDF document text
    • http://reyazahmad.bscsaoner.in/ckfinder/userfiles/files/62005876450.pdfIn PDF document text
    • http://palmdale.thepokeluau.com/uploads/files/37035858294.pdfIn PDF document text
    • http://agierresrl.it/userfiles/files/52160204865.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/kegememubafogakajo.pdfIn PDF document text
    • http://windmill-bv.com/userfiles/files/65726937087.pdfIn PDF document text
    • https://dawnraytech.985.tw/data/file/userfiles/files/nukefudisebujilezowiwedub.pdfIn PDF document text
    • http://sxsasa.org/images_fck/file/1632586227.pdfIn PDF document text
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614476800d8c1---dorikuwimalupivedez.pdfIn PDF document text
    • http://rund.cz/UserFiles/File/98111329338.pdfIn PDF document text
    • http://scpt.it/userfiles/files/nuzozefigegetasaxozo.pdfIn PDF document text
    • http://salukool.ee/upload/userfiles/file/mebujowotaxodivogazizekin.pdfIn PDF document text
    • http://s2ipower.com/survey/userfiles/files/60853549514.pdfIn PDF document text
    • https://csp-pub.com/stockages/files/61757009978.pdfIn PDF document text
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/f6ji2e6rgtjpkn4of498v89dgg/mavag.pdfIn PDF document text
    • http://www.taimaobi.com/admin/ckfinder/userfiles/files/35324760830.pdfIn PDF document text
    • https://iaido-iaijutsu.ru/userfiles_exc/32978324364.pdfIn PDF document text
    • http://bularz-auto.pl/images/userfiles/file/nubibogotup.pdfIn PDF document text
    • http://jinshi66.com/uploadfiles/files/58228180288.pdfIn PDF document text
    • 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_off0000af56.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF56 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c76d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC76D 10696 bytes
SHA-256: bbbfa5046a89c9f1493da00f28bb1620bf99c50514a048065a1f7743b98589cf
font_02_sfnt_off0000dfd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFD9 17872 bytes
SHA-256: 8c0734447b3d5433f8d8b6b03b0be72360f5f7558ff927e8568c03616c19f834