Malicious PDF — malware analysis report

Static analysis result for SHA-256 8db143d922c77598…

MALICIOUS

PDF

74.0 KB Created: 2021-03-11 16:09:04 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: c3b89977794ed77f5e3af5797aefbeae SHA-1: 67037c6fedbf01867728a482ac39bf36c7b0e39b SHA-256: 8db143d922c77598ed60a23629433f458859134cbdd6b5dd421169acae9bc555
126 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 pointing to disposable hosting, suggesting a link farm or SEO spam operation. The ML classifier strongly indicates maliciousness. While no scripts were explicitly extracted, the presence of numerous external URIs and the PDF structure itself are indicative of malicious intent, likely to drive traffic to potentially harmful sites or for phishing purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://kuzutuzo.ru/award?keyword=examkrackers+101+passages+biology+pdf PDF link annotation
    • https://bubosetew.weebly.com/uploads/1/3/4/5/134515161/kibubebudomavav-fanul.pdfIn PDF document text
    • https://numurivigafezu.weebly.com/uploads/1/3/4/3/134390613/b8cee169.pdfIn PDF document text
    • https://zifofuxe.weebly.com/uploads/1/3/5/3/135386801/657157.pdfIn PDF document text
    • http://kezekimoridim.22web.org/clat_question_paper_with_answers.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://uploads.strikinglycdn.com/files/8be55d23-2a74-4215-a509-f33bfef656c0/berserk_manga_ending_date.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fe43c2c1-245d-45a1-afba-17a290c8c0dc/aspiracion_de_secreciones_tecnica_abierta_en_pediatria.pdfIn PDF document text
    • http://tudegelufer.rf.gd/xukamananexapowuga.pdfIn PDF document text
    • https://s3.amazonaws.com/dupula/nujeketes.pdfIn PDF document text
    • http://togujekunigek.rf.gd/80748896417.pdfIn PDF document text
    • https://s3.amazonaws.com/norozovijalu/annamalai_songs_in_tamiltunes.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3ba2e34a-687b-4e5e-a2ac-be2d9e88de6b/27483465097.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f0731cbc-937a-44d4-baf8-7181c17d404e/logitech_z623_2.1_channel_computer_speaker_system_review.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ec7322b6-f498-45c8-b856-c272862cf16d/what_is_the_best_mod_manager_for_fallout_new_vegas.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e4153920-f5dc-4b25-8575-037df5f02021/you_have_been_asked_to_draft_a_document_related_to_evidence_gathering_that_contains_details.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0d60aa43-e8da-4fa1-bedf-4e78c2224227/61324043555.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cca05a60-0971-4507-9595-dab4d59a7279/migelajinibafajaguluwu.pdfIn PDF document text
    • https://s3.amazonaws.com/meludav/numosi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b3bc5cc7-f4df-42e5-b896-47975c1f7054/54292820872.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b34b4128-fe03-436e-b116-a53180ab59f5/30139510366.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4eec529b-af7c-4880-9c50-98501435c84a/43509947541.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/aac615bf-6014-422b-be3a-7b2da0010bdd/45222517005.pdfIn PDF document text
    • http://nekufijazenog.epizy.com/fatowulujiretagolujakiman.pdfIn PDF document text
    • https://s3.amazonaws.com/jefazaxal/action_plan_template_for_project.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d524.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD524 5604 bytes
SHA-256: 1d28648f884f0f70d556fb1836356a375e45782746b4337c981723bcaa6d3845
font_01_sfnt_off0000e83a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE83A 10744 bytes
SHA-256: cfcc7af221eb6ac316f756f9ee4ebf1e6bed12c8f9153e4bb085ed53ac371ef7
font_02_sfnt_off00010c67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C67 4324 bytes
SHA-256: ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3