Malicious PDF — malware analysis report

Static analysis result for SHA-256 21af084ecb885317…

MALICIOUS

PDF

80.6 KB Created: 2021-03-28 15:29:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 81aedf4afbe3ae9746d5d7adba23521b SHA-1: d1c3a41dd812d015cb809684aa49d190cd7b6af8 SHA-256: 21af084ecb8853173d5feb5ed1af3ef9ab69cc9760d69edd00442ef9c2dd66a7
194 Risk Score

Malware Insights

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

This PDF file is identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm designed to distribute malware. The document body, though heavily obfuscated, contains references to 'wkhtmltopdf' and a date, suggesting it was generated programmatically. The presence of numerous external links, many hosted on disposable domains, indicates an attempt to redirect users to malicious payloads, likely disguised as free downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 7

  • 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.
  • 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://jumiwimov.ru/award?keyword=building+construction+punmia+pdf+free+download PDF link annotation
    • https://cdn.sqhk.co/sosexazefip/hhgehic/reretexemazepu.pdfIn PDF document text
    • https://teduzagegoxow.weebly.com/uploads/1/3/4/4/134400331/muwas.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4380867/normal_5fe4acd4e363e.pdfIn PDF document text
    • https://cdn.sqhk.co/rirerujel/fachi0n/mizijiwudugixureperu.pdfIn PDF document text
    • https://zisafidavilux.weebly.com/uploads/1/3/2/8/132814196/wipedu_pigamiropugiman.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369775/normal_603bf97a08635.pdfIn PDF document text
    • https://dakusarifupufa.weebly.com/uploads/1/3/3/9/133997242/rerozobirenimopisu.pdfIn PDF document text
    • https://cdn.sqhk.co/ragejeli/ZgijjjU/xagubitip.pdfIn PDF document text
    • https://cdn.sqhk.co/soxesemu/iaihejg/91278258058.pdfIn PDF document text
    • https://jabenawonidibe.weebly.com/uploads/1/3/5/3/135385032/biregoraje.pdfIn PDF document text
    • https://cdn.sqhk.co/xurunesijud/higgyie/rotator_cuff_pain_location.pdfIn PDF document text
    • https://cdn.sqhk.co/zexoribuj/Zjdighj/kelefaviv.pdfIn PDF document text
    • https://cdn.sqhk.co/minamojazi/gidrtvM/telepsychiatry_jobs_pennsylvania.pdfIn PDF document text
    • https://cdn.sqhk.co/pivokazi/BhbLAnz/fallout_wasteland_warfare_rpg_expansion_book.pdfIn PDF document text
    • https://kalepadakib.weebly.com/uploads/1/3/1/6/131637037/gosonepom-warogazutexamer.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://51bf459c-6b46-41b0-863f-532cf8a77e0d.filesusr.com/ugd/2eedf1_c937be3b807c46899b44233978d9f9b2.pdf?index=trueIn PDF document text
    • https://3568c1c9-c281-4b9a-9ea9-d5d291e0176b.filesusr.com/ugd/e5d8db_77f677d03e40414c8ee610597e012439.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/32abbd01-e907-43cb-8f46-f7d884312583/how_much_is_a_new_engine_for_a_2013_chevy_equinox.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f300bf5d-a13e-41c1-8af5-2043d38312d8/garmin_2689lmt_price.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8bed92e4-45da-4985-b0c4-5814e961ba1b/damasio_the_strange_order_of_things.pdfIn PDF document text
    • https://0e098354-e5d1-4afc-9be7-763a70ae5e44.filesusr.com/ugd/ef253e_1042d1f4246743c19f3cfba7886a0a42.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/613d8fb8-36fd-49dd-92ad-a3c7153dbc20/strategic_human_resource_management_notes_mba.pdfIn PDF document text
    • https://8569cc17-8b2a-4187-ace0-95b0550b99f0.filesusr.com/ugd/d6eede_a588de5fb1294c458abbc94a6fcf5ad2.pdf?index=trueIn 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_off0000ef95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF95 5500 bytes
SHA-256: 72c0fb5973a69af05f1714d19f43aca8d60b014b135c36f4191cb8dc40ba0b04
font_01_sfnt_off0001023c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1023C 10636 bytes
SHA-256: a35558df70b75a4488144d90b30df4ab1ba67e235027510fc753a24d93354a52
font_02_sfnt_off000126b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126B4 4324 bytes
SHA-256: 7f6049e5011acf0e8581793f2bc2bb947aac2929fdb77abc318b2a6155c1ef71