Malicious PDF — malware analysis report

Static analysis result for SHA-256 8173736a3d8f8fc5…

MALICIOUS

PDF

74.8 KB Created: 2021-06-04 14:41:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 7f21005105a2f9a8a1482bbcdfc0d95c SHA-1: edc84af5e45c6c799c5a0762537a65d941a2ba51 SHA-256: 8173736a3d8f8fc5c7855f46b47bf1e621a54d2e03dd1e70a676638a265265ea
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous embedded URLs pointing to link farms hosted on disposable domains, a common tactic for phishing and malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. While no scripts were explicitly extracted, the PDF structure and URL patterns suggest it's designed to trick users into clicking links that lead to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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
  • 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://drafthe.ru/pbw?utm_term=new+millennium+english+workbook+grade+1+pdf+download PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4464313/normal_5fe6ddbc30b75.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4381962/normal_60604db652eff.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4377408/normal_604f7a6f87b62.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4485828/normal_6007b881748e9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4404964/normal_6015296d7eef5.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4501775/normal_600159992a964.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379849/normal_5fd635ae4b960.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4444648/normal_60b02b1a4c4d7.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4481273/normal_60b1be834810c.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4483359/normal_6007eeef590dc.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4405651/normal_5fecb9bfbad01.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/98f0e7cd-62f1-48d2-b9eb-d130d1110c86/cretors_popcorn_machine_price.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e4ca42be-adf0-482f-870e-f301c85ad252/first_principles_thinking_reddit.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6530f1b7-9db9-4de6-9a6d-a5fa9aac3a48/what_percent_of_the_population_has_diabetes.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7713f8eb-70bd-4d07-80d9-fed6c7341be7/juwedurib.pdfIn PDF document text
    • http://polubisoxuwo.pbworks.com/f/zavivu.pdfIn PDF document text
    • http://gupiguna.pbworks.com/w/file/fetch/144584625/how_to_get_diamonds_in_mobile_legends_for_free_2020.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ed9cf898-bf1c-4ad9-884e-ad789c326663/43123548028.pdfIn PDF document text
    • http://mukibilevejo.pbworks.com/w/file/fetch/144481008/kinemaster_latest_mod_apk_2021.pdfIn PDF document text
    • http://sizolasipape.pbworks.com/f/bleach_brave_souls_lvl_200_guide.pdfIn PDF document text
    • http://dajodovilav.pbworks.com/w/file/fetch/144553647/what_days_does_allegiant_air_fly_to_punta_gorda.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_off0000e29e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE29E 5772 bytes
SHA-256: d73dd8f53b2af36ee21fe8e7951865afe7bb00f9d671f155447821ea5a84aae2
font_01_sfnt_off0000f635.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF635 10856 bytes
SHA-256: 283833f35152a71cac6f58e65e39a244d27b95367f32b3afec631297b4e81b77