Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8f8bbf89ac78c3b…

MALICIOUS

PDF

79.5 KB Created: 2021-05-11 17:24:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 10b8276ea78652e99e6e04a3ad63b2a2 SHA-1: 28d336ef85d4a46d38e08b9803d7a8b0e5562c67 SHA-256: d8f8bbf89ac78c3ba96a52b4f58583efa5fb155a73e7281746a98524b6cd4f52
126 Risk Score

Malware Insights

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

This PDF document functions as a link farm, directing users to numerous external URLs under the guise of an English 101 college syllabus. The PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics indicate a high volume of links hosted on disposable domains, suggesting a malicious intent to distribute potentially harmful content or engage in SEO manipulation. While no scripts were explicitly extracted, the presence of embedded URLs and the ML classifier's high confidence score point towards a malicious document designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 5

  • 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.
  • 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://druttle.ru/strik?utm_term=english+101+college+syllabus PDF link annotation
    • https://zetoruribafepa.weebly.com/uploads/1/3/1/4/131452904/7098569.pdfIn PDF document text
    • http://larebalin.mypressonline.com/69340792534.pdfIn PDF document text
    • https://cdn.sqhk.co/gotofebelu/hif7wg3/catfishing_definition_urban_dictionary.pdfIn PDF document text
    • https://cdn.sqhk.co/keximovib/dqrjYtR/doralogikuma.pdfIn PDF document text
    • https://cdn.sqhk.co/pikikunifav/ibiiR2r/world_of_warcraft_classic_lockpicking_leveling_guide.pdfIn PDF document text
    • https://cdn.sqhk.co/dizoketa/ksLhdha/bengali_movie_song_sathi.pdfIn PDF document text
    • https://cdn.sqhk.co/rapovixovuti/ajggdie/torojamowinuzomup.pdfIn PDF document text
    • https://cdn.sqhk.co/zowonefaso/7ygh0I5/vuxegasuwex.pdfIn PDF document text
    • https://cdn.sqhk.co/vekunego/zwidghv/dipawasulanisesugulemij.pdfIn PDF document text
    • https://jadigitunuw.weebly.com/uploads/1/3/4/6/134672933/8578093.pdfIn PDF document text
    • https://wakukaxowemaba.weebly.com/uploads/1/3/5/3/135303752/0590ff88d21e.pdfIn PDF document text
    • https://nekamefirojes.weebly.com/uploads/1/3/0/7/130739169/8813173.pdfIn PDF document text
    • https://cdn.sqhk.co/ravusigi/jhgdQie/shareit_apk_mirror.pdfIn PDF document text
    • https://rimedugomo.weebly.com/uploads/1/3/0/7/130740195/cf9db801e.pdfIn PDF document text
    • https://cdn.sqhk.co/xororofomed/hbhdqij/devap.pdfIn PDF document text
    • http://ponemofetu.scienceontheweb.net/taylor_kitchen_scale_not_working.pdfIn PDF document text
    • https://cdn.sqhk.co/zizenozi/jfjhgh6/belated_birthday_card_template.pdfIn PDF document text
    • https://medivikula.weebly.com/uploads/1/3/4/8/134883054/xubipanimuf.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/134f190c-1440-4cf8-8b3e-812835c14ef6/budigomimejotagajume.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d3fcdc36-78d3-45de-ad3b-4fbad40504e9/doom_2_level_16_suburbs_walkthrough.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0f21955c-8f8d-4ec6-97ce-890c99b6eacf/xopalokes.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/94ed84a6-41bf-4305-9e66-b7a21dde5bcb/52919647279.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a5bf8590-2e7f-4127-b900-0204dbafa1a6/kulewumepifaduwifuxuvuxew.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_off0000f72c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF72C 5360 bytes
SHA-256: fef442ae96a2faf998e4ec95b80da940b2691488d910d5c07b8d60a41bcc063a
font_01_sfnt_off0001097b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1097B 11416 bytes
SHA-256: 9c1b9da13e9143ebdd188570962c1268b6f87cde3936ca32dcb88b8dafec7347