Malicious PDF — malware analysis report

Static analysis result for SHA-256 21d876080c529c5d…

MALICIOUS

PDF

84.4 KB Created: 2021-03-23 08:12:36 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-31
MD5: 36499208ab160927c63c02b6e06f399a SHA-1: e94946c7f48ac6c5255a2d3368c56a1d135c6ecd SHA-256: 21d876080c529c5da010c72f0f829605b67657bbcdcdc7579c8b46d5f86c5ba5
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many of which point to disposable hosting services and are presented with query parameters suggesting a lure for mobile security or antivirus applications. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the structure suggests a link farm designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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
  • 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://mezovuduw.ru/123?utm_term=mobile+security+antivirus+mod+apk PDF link annotation
    • https://cdn.sqhk.co/gujadozede/eiagdoV/81033803211.pdfIn PDF document text
    • https://cdn.sqhk.co/jasowipe/mjarDhd/hyperion_launcher_supreme_apk.pdfIn PDF document text
    • http://rusakadovub.sportsontheweb.net/argumentation_and_debate_book.pdfIn PDF document text
    • https://cdn.sqhk.co/rowofabuf/gigd0GX/2992234019.pdfIn PDF document text
    • http://nitanupemil.mygamesonline.org/bigaxasi.pdfIn PDF document text
    • https://cdn.sqhk.co/woledowo/OhgOOYv/36559676953.pdfIn PDF document text
    • https://faxojoduso.weebly.com/uploads/1/3/5/3/135351685/ac210309f5.pdfIn PDF document text
    • https://nutifikidejuz.weebly.com/uploads/1/3/4/3/134347692/fofomo-lukute.pdfIn PDF document text
    • https://cdn.sqhk.co/zevinikiwi/ezkShj2/bible_song_offline_with_lyrics.pdfIn PDF document text
    • http://vuwazakuzasoz.iblogger.org/74837742355.pdfIn PDF document text
    • https://kivowitu.weebly.com/uploads/1/3/4/7/134703836/vijidabozatafi.pdfIn PDF document text
    • http://nageramuvepom.mywebcommunity.org/what_trees_grow_well_in_central_florida.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/ff28ab5a-7420-4de0-aab6-7d45d17cd510/gomokaxifenolud.pdfIn PDF document text
    • http://zininorenedalo.onlinewebshop.net/affective_fallacy.pdfIn PDF document text
    • http://kavibajegis.onlinewebshop.net/94509761729.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3c22dff9-d623-4c07-a14b-6c47f9f48463/how_to_cook_gammon_steaks_on_a_george_foreman_grill.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8fd2e239-e8b4-457e-aa30-a0e0b6e24861/72375437857.pdfIn PDF document text
    • http://tuvivitir.rf.gd/automatic_process_control.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3634affb-e826-4daf-8e7b-9396ab0c49b6/engineering_problem_solving_with_c_3rd_edition_solution_manual.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eb1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB1A 5592 bytes
SHA-256: 98a663614c7b085cc3f5736faa147c162ff5a911130c3fe3a72ccf110373cf27
font_01_sfnt_off0000fe13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE13 1800 bytes
SHA-256: a36eee06fef6ce219692c4ec918276ac99413e4fd1e3666e4031624f9289d620
font_02_sfnt_off000106a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106A0 10808 bytes
SHA-256: 1f7b9878434245de2f50c3421ae94c7fa01ed889913b770d7d8ab1d7cc3cd1c8
font_03_sfnt_off00012bfd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BFD 16364 bytes
SHA-256: 6d0ac78d3bf371d78da37f88410d459affa0dd650fcabdd895a9dec89ce0cebb