Malicious PDF — malware analysis report

Static analysis result for SHA-256 b54c8e0ec8f0536f…

MALICIOUS

PDF

74.8 KB Created: 2021-06-01 09:49:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-24
MD5: cd0542ee165e0a25b4e52717104197c8 SHA-1: 8b41cc7bc84d769d7dab2feb0d60da1128ea788c SHA-256: b54c8e0ec8f0536f4ad443f47fabd54d4082aef0ebe8ee8527fffe226ae99dbe
142 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, many hosted on disposable domains, suggesting a link farm or redirection scheme. The document body, though heavily obfuscated, appears to reference 'resignation email template' and 'wkhtmltopdf', indicating a potential lure. The ML classifier strongly flagged this PDF as malicious, and the presence of numerous external URIs points towards a phishing or redirection attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 7

  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://medvor.ru/pbw?utm_term=how+to+write+a+resignation+email+template PDF link annotation
    • https://piwobovolan.weebly.com/uploads/1/3/5/3/135388479/136ef30130d7f.pdfIn PDF document text
    • https://pubogovivewata.weebly.com/uploads/1/3/2/3/132302724/makuk.pdfIn PDF document text
    • https://jikufowawuful.weebly.com/uploads/1/3/2/8/132814232/banidefisado.pdfIn PDF document text
    • https://gewupokisata.weebly.com/uploads/1/3/4/6/134606569/4203598.pdfIn PDF document text
    • https://mujilaku.weebly.com/uploads/1/3/4/3/134389228/supuzowuzuta.pdfIn PDF document text
    • https://nalatuzub.weebly.com/uploads/1/3/4/3/134324595/wemusivono.pdfIn PDF document text
    • https://menuvudojowakap.weebly.com/uploads/1/3/4/5/134594867/ribisejuxita.pdfIn PDF document text
    • https://rijifupipi.weebly.com/uploads/1/3/1/4/131453414/5495458.pdfIn PDF document text
    • https://modatuna.weebly.com/uploads/1/3/7/5/137509789/pexesuzokopesa.pdfIn PDF document text
    • https://lozofuxoxezutuw.weebly.com/uploads/1/3/5/3/135303337/xeposulavogus.pdfIn PDF document text
    • https://kapofered.weebly.com/uploads/1/3/2/6/132680839/rufomevur.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://tisowowuduwe.pbworks.com/w/file/fetch/144417753/3787194316.pdfIn PDF document text
    • http://zexowisam.pbworks.com/f/9_snf_almanca_kitab_cevap_anahtar.pdfIn PDF document text
    • http://paderukut.pbworks.com/f/how_to_adjust_accelerator_pedal_position_sensor.pdfIn PDF document text
    • http://fixunomavow.pbworks.com/w/file/fetch/144450015/ample_guitar_f_vst_free_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f90ed6a9-0036-40be-9f77-cfd08d4b87d3/popinuwedexafuxoregagu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/73232a0c-5075-490f-956a-ad999f6e4c71/gb_whatsapp_download_2021_new_version_7.90_free_download_apk.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4fe1a7a8-85d9-4a06-b9df-3216a2849d4b/kitegenivigasowufik.pdfIn PDF document text
    • http://sorawako.pbworks.com/f/cs_1.6_silent_aimbot_cfg.pdfIn PDF document text
    • http://dipoziw.pbworks.com/w/file/fetch/144439515/38089232020.pdfIn PDF document text
    • http://zelovoguvunu.pbworks.com/w/file/fetch/144427155/44772556078.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_off0000e6dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6DD 5192 bytes
SHA-256: 2a2902508a5158c3ebeef4b9461176ec768f2950d7ceeff6a25e1eab81db6247
font_01_sfnt_off0000f881.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF881 10756 bytes
SHA-256: 45df0313ec4e1fba9fda315c37c4b6f804d16b9254ae55af28f722e82943e56f