Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8ef86c0c93d5707…

MALICIOUS

PDF

86.4 KB Created: 2021-09-02 23:21:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: b5c51085eb4abf0280af4519a913ceff SHA-1: 197d3d68b15074356a283805795672fddb5e97f7 SHA-256: b8ef86c0c93d570748d420c6a89b2c54f288e84982a10275a7f524ddd42df822
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection as a phishing trojan. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and other disposable hosting domains. The primary purpose appears to be redirecting users to malicious content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://shethof.ch/cgi-bin/dynamisch/file/jakekikifewuxid.pdf In PDF document text
    • https://vaytieudungtragop.com.vn/wp-content/plugins/super-forms/uploads/php/files/ujrkv2lfvteggnqcn0g974m0rg/99105598006.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/ce890u20bdklcis7rvrklq89t7/zikazoxafosakepo.pdfIn PDF document text
    • http://suara.ru/img/file/zilirudup.pdfIn PDF document text
    • http://mhinflatable.com/upload/file/60865791309.pdfIn PDF document text
    • https://sharidendesignasphalt.com/wp-content/plugins/super-forms/uploads/php/files/afe0e8e8673dc8d2465e64e60b662655/pogedositasipa.pdfIn PDF document text
    • https://angkoronetour.com/userfiles/file/sozulivemomodijufekan.pdfIn PDF document text
    • http://matonaklawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/boxegetetufev.pdfIn PDF document text
    • https://immo-macedo.lu/userfiles/files/18613932489.pdfIn PDF document text
    • https://varbackaforskola.se/ckfinder/userfiles/files/mupizujexav.pdfIn PDF document text
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606fa9e55ddf4---88947191076.pdfIn PDF document text
    • https://lanjutpt1.com/contents/files/19738208418.pdfIn PDF document text
    • https://anmimar.com/royal/userfiles/file/xovuximaluvabejimuneput.pdfIn PDF document text
    • http://alfavit.tv/userfiles/file/pepavukawiwewenat.pdfIn PDF document text
    • http://elmiraclassiccountry.com/wp-content/plugins/super-forms/uploads/php/files/km4464198kb6ucb9nflitbbqu6/7946323413.pdfIn PDF document text
    • http://sts-logistika.ru/wp-content/plugins/super-forms/uploads/php/files/5dac60b92151e2a0fc27c48472c8b8f0/zijobeluxezusowofezi.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a40641c6c66---roporagozudikezoniwexura.pdfIn PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085694e91837---58381977836.pdfIn PDF document text
    • https://defi128.com/userfiles/files/70965498705.pdfIn PDF document text
    • http://mineraux-et-lithotherapie.fr/ckeditor/upload/files/nezidopojegafu.pdfIn PDF document text
    • http://dermaktif.com/imgup/file/xafanuvogewiberijuf.pdfIn PDF document text
    • http://eiak.org/upload/editor/files/20979831489.pdfIn PDF document text
    • https://matrixx.lu/images/50595302046.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/5brdrguqhj38uk9d23o0a0eed8/31420835936.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16116dc4ae0462---kebukoledelaxasawer.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=serutan+es+manual+besiPDF 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_off0000efdc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFDC 10464 bytes
SHA-256: 0b00bdc402d5eab1919f90d1905bc0a7ea71eb6fcadc29502340235887f8918a
font_01_sfnt_off00010795.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10795 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011fa7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FA7 17528 bytes
SHA-256: 620d0103b86a42329f14f605ae1fd02bd341d1615ff8040576f3a87682fd18db