Malicious PDF — malware analysis report

Static analysis result for SHA-256 81a3d02217095af1…

MALICIOUS

PDF

82.8 KB Created: 2021-09-19 15:34:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: d304ebb9be388ba87196d33577494c05 SHA-1: 8df69fc09aef74acfbfd2666fa28cde668c65296 SHA-256: 81a3d02217095af103e824c1401f91cd2fad826ab9c3102b1fff9f8a59580399
196 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The 'SE_BROWSER_INSTALL_LURE' heuristic strongly suggests the document is designed to trick users into installing malicious software by posing as a necessary update or extension. The presence of numerous URLs, many hosted on compromised or disposable domains, further supports a phishing or malware distribution scheme. No scripts were extracted, but the overall structure and heuristics point to a social engineering attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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 http://sin-hua.org/userfiles/dowiwelilabu.pdf In PDF document text
    • https://www.okcfarmersmarket.com/wp-content/plugins/super-forms/uploads/php/files/55bd6c497ddf4e9aa533630350f72adc/57692087967.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/a010ea8bddc6b46df48cd852883cda3f/resufuluvajenafufomew.pdfIn PDF document text
    • http://webspace.mysdam.net/images/newsletter/files/pozakapox.pdfIn PDF document text
    • http://iuoooo.com/filespath/files/20210908224744.pdfIn PDF document text
    • http://brilspa.ro/userfiles/file///xuvepujikojovefani.pdfIn PDF document text
    • https://stmarys-perthamboy.com/upload/File/12339014723.pdfIn PDF document text
    • http://happysmilecard.com/uploads/files/34952241271.pdfIn PDF document text
    • http://neonatal-surgery.ru/userfiles/files/kerapatenunozafajizip.pdfIn PDF document text
    • http://carzip.biz/files/uploads/files/88124237812.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/16147078992903---66432954796.pdfIn PDF document text
    • http://hrzservices.com/uploadfiles/file/towotomepabi.pdfIn PDF document text
    • http://saxonrt.hu/img/userfiles/files/wikolojatanu.pdfIn PDF document text
    • http://pop-around.com/file_media/file_image/file/4908625795.pdfIn PDF document text
    • http://speckrepeg.by/UserFiles/files/wufezeritopati.pdfIn PDF document text
    • http://another-partner.morefriendship.com/upload/files/wopixajadagojupekalawo.pdfIn PDF document text
    • http://wiskind.com/filespath/files/20210915191459.pdfIn PDF document text
    • https://drbumbnursinghome.in/ckfinder/userfiles/files/90928759346.pdfIn PDF document text
    • http://costruzionibulagna.it/userfiles/files/monowovukavavol.pdfIn PDF document text
    • http://wxdyzs.com/userfiles/files/senosiweba.pdfIn PDF document text
    • http://dispensapertutti.com/userfiles/files/46309280522.pdfIn PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/9b980ec866504d70a77d12857afde13e/sowor.pdfIn PDF document text
    • http://positiveforce.in/uploads/files/zegisifiwagigajalobe.pdfIn PDF document text
    • https://mpressivelabels.com.au/application/third_party/ckfinder/userfiles/files/83597553932.pdfIn PDF document text
    • http://nakamurasangyou.jp/app/webroot/uploads/files/79754595035.pdfIn PDF document text
    • http://www.sun-green.eu/ckfinder/userfiles/files/48265261044.pdfIn PDF document text
    • http://fosterfreezesantarosa.com/uploads/files/kavizobulanadowuburixo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=install+android+system+webviewPDF 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_off0000e083.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE083 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f89a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF89A 10768 bytes
SHA-256: 16b7e925dc5bd450920830c40b412e08b5299b54fa0c0b1e76aeaff197fed9ed
font_02_sfnt_off00011167.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11167 17108 bytes
SHA-256: 1461f48bc44b7470c8ab69dda9a5193f5da7b1847d98a6192578c8c6fc3e9e59

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