Malicious PDF — malware analysis report

Static analysis result for SHA-256 c6a33b3578a3e516…

MALICIOUS

PDF

77.9 KB Created: 2021-05-20 21:07:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 31ab7bfa3d84e72e2537b6ae45ba686f SHA-1: 7b7e173288f9d6c8b54f9b6a64d486e7669137e9 SHA-256: c6a33b3578a3e5167ed5d2c515c4e70c3d495611696a7b06223702b43d545c56
194 Risk Score

Malware Insights

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

The PDF file contains numerous external links, with a critical heuristic identifying it as a link farm on disposable hosting. One of the primary URLs, 'https://xezojetit.ru/strik?utm_term=san+bernardino+food+handlers+card+practice+test', is flagged as unknown reputation, suggesting a malicious intent. The ML classifier and ClamAV detection strongly indicate maliciousness, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://xezojetit.ru/strik?utm_term=san+bernardino+food+handlers+card+practice+test PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4444098/normal_603013d893425.pdfIn PDF document text
    • https://tesevazaxuj.weebly.com/uploads/1/3/4/4/134476418/mobexukadijesog.pdfIn PDF document text
    • https://memuwumobodedo.weebly.com/uploads/1/3/5/9/135974490/fazizumeninodesonev.pdfIn PDF document text
    • https://tepadomuxufebe.weebly.com/uploads/1/3/1/3/131382092/bugamugawokiw.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421966/normal_600c0fbe28688.pdfIn PDF document text
    • https://gemujofu.weebly.com/uploads/1/3/4/3/134372819/tebudidew.pdfIn PDF document text
    • https://kebufuwotum.weebly.com/uploads/1/3/4/0/134040355/813160.pdfIn PDF document text
    • https://monogelifanalo.weebly.com/uploads/1/3/5/3/135387447/vituma.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417314/normal_5fdc761276d95.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/2120bd82-3084-4074-9b44-4a6783a1ca67/html_css_javascript_templates_free_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6b358b49-397b-44ad-8f24-0f76d6f9eb55/rigimaloreginanix.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8c5cafe1-1197-4c98-89af-4d7dafc4fbc3/jikinemi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/60ed7b55-3699-40a2-89a9-9cabe63bd526/73281100786.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3219c664-5f75-4f71-98aa-1567eff0908a/john_deere_lawn_tractor_battery_charger.pdfIn PDF document text
    • https://s3.amazonaws.com/tawovojo/10268869093.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f9c493a7-69db-4adb-af27-683091e33905/1734_ib8_wiring_example.pdfIn PDF document text
    • https://s3.amazonaws.com/toliwudalamem/words_their_way_spelling_inventory_primary.pdfIn PDF document text
    • https://s3.amazonaws.com/faluzotixupi/64514133686.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/94f62d7a-7d59-4562-8cc5-edc044c669f5/my_honeywell_wireless_thermostat_is_not_working.pdfIn PDF document text
    • https://s3.amazonaws.com/nufidibodudulad/app_connect_vw.pdfIn PDF document text
    • https://s3.amazonaws.com/mibiwivanetuj/zenipiwawenutu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8b94016c-5dcb-4ed6-be04-e7aa2a13e9ed/cual_camino_descargar.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e26b9ba2-ee5c-48c5-937b-3b788af8cf90/kazajijudujovoxotojotozu.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f0f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0F9 5488 bytes
SHA-256: 29cd95bb3b5e96e5c368080fdbbd577c07d6c0c8bb09aaef0369546478d0d9b3
font_01_sfnt_off00010395.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10395 11208 bytes
SHA-256: 0ff66629753a9894e8022e476e6aba2276826087aea48b389f4495bf581340d7