Malicious PDF — malware analysis report

Static analysis result for SHA-256 af008c88c6b9fdfe…

MALICIOUS

PDF

84.6 KB Created: 2021-05-08 01:47:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: cee9b7e13b4c688393363cdb07dc50a1 SHA-1: ab1c0a98f69651b2edbfebec3c790d65a36788a0 SHA-256: af008c88c6b9fdfe06e693a9ebac8b990040d2d2ffd096ed7b9f84885ebbc4b6
226 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a fake-CAPTCHA lure. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Fake CAPTCHA / human verification prompt high SE_FAKE_CAPTCHA
    Document displays a fake CAPTCHA or human-verification prompt — used to trick users into running commands or pressing keyboard shortcuts
  • 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://gimoguvi.ru/strik?utm_term=how+much+does+an+airstream+bambi+cost PDF link annotation
    • http://xerujupuje.sportsontheweb.net/adobe_scan_to_app.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4404105/normal_5ff52acad5adb.pdfIn PDF document text
    • https://cdn.sqhk.co/temejikowewa/jjhFogi/bevuxarijagezuporukezifis.pdfIn PDF document text
    • https://cdn.sqhk.co/xewumoxu/hijbiid/21344912727.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4384301/normal_60636bf97c2c3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4491414/normal_602fd67372dac.pdfIn PDF document text
    • http://zujejilolo.scienceontheweb.net/arthashastra_tamil_download.pdfIn PDF document text
    • https://cdn.sqhk.co/rureroso/UijwDgi/5236091707.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4384822/normal_6052d2cb0f7e7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4380213/normal_601359a28b3ec.pdfIn PDF document text
    • http://gitikirazidapi.medianewsonline.com/anthelmintic_plants.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4488141/normal_601e640a1d1b7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4462992/normal_60382617200ec.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/4591a45c-59a7-458f-a9b8-4bc93a69d9eb/city_mini_gt_double_car_seat_adapter_nuna_pipa.pdfIn PDF document text
    • https://de461234-8179-4892-b46d-67dc01ae00af.filesusr.com/ugd/69bbc5_b39c613cef204fa6bbefc53951eb282c.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/c3c5266f-42f5-4cae-99dd-13722ff525c0/sojugaweminiporolo.pdfIn PDF document text
    • https://9cfe8934-cc69-4f76-a0d0-2e9849ea4530.filesusr.com/ugd/fd9558_83630e4902e64124bfc3bceaac44c96d.pdf?index=trueIn PDF document text
    • http://liroporuki.myartsonline.com/online_banking_services.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1a01b077-e2b3-4b34-ae50-c2a27daef81a/77153352621.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ef920b52-715f-40a4-baf7-9c9da2613cbd/jafokibatibateduwesur.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_off00010a09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A09 5340 bytes
SHA-256: b334ef4be73d72ea6f4dffd7b22b908982d998266b9c13224b4cc002df6ee68e
font_01_sfnt_off00011c0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C0F 11392 bytes
SHA-256: 388fe96ec41f655b29a75448680cc2f29d5f065aa4bb5dd4762f20cecfb551e8