Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b5ecdc0c9026188…

MALICIOUS

PDF

79.5 KB Created: 2021-09-11 11:01:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 6890d9fe05e56682586df80ed39ebd78 SHA-1: 785921fed4a1932a1fc56036d7a3ff2866077120 SHA-256: 8b5ecdc0c90261886ab95fd91cd4f6c6e6791cf25a8933837cb30bbfbf6717d0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. The file contains numerous external URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting it functions as a link farm for phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://medvor.ru/uplcv?utm_term=como+aumentar+memoria+de+almacenamiento+interno+android PDF link annotation
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/c7abd7089385d8ce536c61d627817ade/jiwupinugilodijatimiwi.pdfIn PDF document text
    • http://xfswchem.com/upload/files/70445148746.pdfIn PDF document text
    • https://parisautotravel.com/wp-content/plugins/super-forms/uploads/php/files/0baqeqikt3jouik70k023kosj7/65409206289.pdfIn PDF document text
    • https://mygenius.ru/admin/ckfinder/userfiles/files/85310124074.pdfIn PDF document text
    • http://johnmichaelharrisonlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/popijolomak.pdfIn PDF document text
    • http://arcadia-fitness.es/userfiles/file/ziwikuzozesefawenamubopel.pdfIn PDF document text
    • http://studiomuraca.eu/userfiles/files/18766411619.pdfIn PDF document text
    • http://reklama-kemerovo.ru/files/files/nurilexikisifatozasuzolom.pdfIn PDF document text
    • http://morgancountyoh.com/userimages/56464184740.pdfIn PDF document text
    • https://calmoinc.com/upload/editor/file/12481294877.pdfIn PDF document text
    • https://www.dynasil.com/wp-content/plugins/super-forms/uploads/php/files/e63cf583a82988bfb4e9c6a3e84cd642/feladigo.pdfIn PDF document text
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134c7051a9f2---39012932515.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/87127d5954d72ea11d17ba28d0e265a4/91886984709.pdfIn PDF document text
    • http://naoshima-habitant.com/images/blog/file/xavitamugajedumebasu.pdfIn PDF document text
    • https://m-astar.com/UserFiles/files/rimaxozop.pdfIn PDF document text
    • https://asmitahrgroup.com/ckfinder/userfiles/files/raguxibujifiwi.pdfIn PDF document text
    • http://sp3siemianowice.pl/userFiles/files/vexuduli.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/rt50lj6epdaqrgpngr1180img7/puzasivitav.pdfIn PDF document text
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/161334f0e5bb69---79203505874.pdfIn PDF document text
    • https://myagenda.myagenda.cz/pictures/editor/files/fadolibanifinefode.pdfIn PDF document text
    • https://sayurmateng.com/contents/files/63667839484.pdfIn PDF document text
    • https://locktactyuma.com/userfiles/file/bobiwakemudiliz.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_off0000d125.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD125 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e937.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE937 17928 bytes
SHA-256: 6a082cc46fd48d44ba677cdedc0c6fba12edb4e7462b815152e0214dcfaed31e
font_02_sfnt_off000116a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116A8 10492 bytes
SHA-256: 3132804683704e7b17d3ac0334cad904d8f949fdb4149b24539e84e4a12733c1