Malicious PDF — malware analysis report

Static analysis result for SHA-256 ba88f85c20774113…

MALICIOUS

PDF

72.2 KB Created: 2021-06-07 03:01:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: bf6b4081469e73b884a8dfa25bd93f96 SHA-1: d5ca250c94be877992b1aacaccebdd04d4dbda6f SHA-256: ba88f85c207741136953809f0420585f11613f367f3077e2743a182a5c4eac74
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous external URIs pointing to other PDF documents, a common tactic for SEO spam or distributing further malware. The presence of embedded URLs and the PDF_SEO_LINK_FARM heuristic strongly suggest this behavior.

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 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://laborke.ru/pbw?utm_term=conceptos+de+salud+p%25C3%25BAblica+y+estrategias+preventivas+un+manual+para+ciencias+de+la+salud+pdf PDF link annotation
    • https://keladita.weebly.com/uploads/1/3/0/7/130739570/dalobopas.pdfIn PDF document text
    • https://zutiwijutorezaz.weebly.com/uploads/1/3/4/3/134354078/6355326.pdfIn PDF document text
    • https://dobumixil.weebly.com/uploads/1/3/0/7/130738680/gofusepimateder.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369768/normal_603f23fa0da7e.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4454299/normal_60b23b3fbc769.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4465559/normal_5fffbf7d26540.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4388420/normal_5fc7e3aae33e8.pdfIn PDF document text
    • https://nuzefamulazoxiz.weebly.com/uploads/1/3/4/5/134582777/02254a286f.pdfIn PDF document text
    • https://madaremowigefin.weebly.com/uploads/1/3/2/6/132681361/nanorirexatusasub.pdfIn PDF document text
    • https://manonerotorupu.weebly.com/uploads/1/3/4/6/134683358/dedivora-jufavenuri-kefubaxidakit.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4448103/normal_603684ce17035.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/bcdeb949-378f-429f-a321-b860253ae902/3019670953.pdfIn PDF document text
    • http://wenitudodub.pbworks.com/f/wukutotowunuda.pdfIn PDF document text
    • http://nubuzefi.pbworks.com/f/tu_tu_hai_wahi_song_free_download_new_version.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f3a271f5-3925-4bbe-96c6-4dda4cd134f5/nusarexonoximugop.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6a5c32e4-3bb8-4540-abda-41bcf14ff78a/30959579809.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/10ed975c-8e49-4a0b-af73-8d7b366c0595/80519639024.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e4b2cc70-3c9c-4caf-9369-e42b1eade645/tofemovimulovifarado.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b3b410c3-af95-41ce-9a9f-36316d46dea4/5398047659.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1a7ca21d-31fb-4304-a93d-742dec0458e7/perfect_english_grammar_reported_speech_exercises.pdfIn PDF document text
    • http://liwuvedesisu.pbworks.com/w/file/fetch/144494316/66597988460.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/09938a89-e68b-40bd-b925-11f209deb64c/rumuzefige.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_off0000d8da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8DA 5796 bytes
SHA-256: e25f11aa9008811f412e81aa967c01af651e05f76bd3172c1f643a958a1936fd
font_01_sfnt_off0000ec57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC57 10776 bytes
SHA-256: 72f74e90ee3c45ed867808c936284d129259a9fbcdfb350949f4c9fd2e0dcc3e