Malicious PDF — malware analysis report

Static analysis result for SHA-256 c73a371b835b8d32…

MALICIOUS

PDF

83.5 KB Created: 2021-06-09 07:11:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: c5faf1dba087e217a97a649bc3f075db SHA-1: ce33ee6daf6b0c8c047d4393c84fbf73cfce4935 SHA-256: c73a371b835b8d32ccd5d161845d3eee6bddce22eabb6493559d75d0dc041835
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 pointing to disposable hosting services, indicative of a link farm or SEO manipulation tactic. The primary URL, 'https://krisoc.ru/pbw?utm_term=tomas+rivera+and+the+earth+did+not+devour+him+pdf', suggests a phishing or malicious redirection attempt. While no scripts were explicitly extracted, the PDF structure and heuristics strongly suggest it's designed to drive traffic to malicious or spammy websites, potentially as part of a phishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9969

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://krisoc.ru/pbw?utm_term=tomas+rivera+and+the+earth+did+not+devour+him+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4372673/normal_60395af57824f.pdfIn PDF document text
    • https://vozutububedem.weebly.com/uploads/1/3/4/3/134372478/9202160.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4452853/normal_60b29fb0eb584.pdfIn PDF document text
    • https://kovelikazaw.weebly.com/uploads/1/3/4/7/134705675/lekifaf.pdfIn PDF document text
    • https://nuruvubapifak.weebly.com/uploads/1/3/1/4/131452890/2334321.pdfIn PDF document text
    • https://finukapaxareb.weebly.com/uploads/1/3/4/4/134494590/9698462.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4425533/normal_5ffbae6001b57.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403946/normal_6021c26d83ea3.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4474998/normal_5fe041a291780.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4443362/normal_6039717124835.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4464541/normal_60218682cb4d9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4464313/normal_5fe74fd93d57f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4447265/normal_6055bde8c06bd.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4463298/normal_5ff4eebc6c137.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/aaa9953e-13fb-49a3-9a8a-e49575924811/10189508224.pdfIn PDF document text
    • http://funinupun.pbworks.com/f/93178675896.pdfIn PDF document text
    • http://nusometa.pbworks.com/f/55742470226.pdfIn PDF document text
    • http://tusoxefum.pbworks.com/f/download_idm_with_full_crack.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1a0cfe59-8da9-4619-a723-68dfb5577b8c/15595465454.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a2e185a7-dd66-4125-bad3-806276101b91/ng_command_not_found_windows.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5478a1b1-9b11-44d0-83eb-d5e3e4641e86/85400084740.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4a2b93f0-066a-4858-ba43-119c772f6a4c/crossover_symmetry_printable_chart.pdfIn PDF document text
    • http://gejigavowule.pbworks.com/w/file/fetch/144916680/statistics_for_business_and_economics_8th_edition_solutions_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cf4f0771-5141-4dbd-b5a0-2f8248b55b0e/how_to_repair_kenmore_washer_dryer_combo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e4e1e580-da20-4737-bec0-d3f11ce2aa4e/71649790673.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a5c50e64-4695-4e3b-9a7f-f40153d332d6/how_to_calibrate_samsung_smart_tv_remote.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4a2ddcd4-3507-477b-bc96-15f0fb422c1f/do_pink_dye_test_have_evap_lines.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f1c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1C0 5256 bytes
SHA-256: 9d9a7e43d5f776369548526f91da333e24a1572ebc208df938747b42391e69d2
font_01_sfnt_off00010376.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10376 10944 bytes
SHA-256: 0d3a2b17fb7ad8be78ddae2e9431f2b088f3d36502a5779c03d58c8a57743816
font_02_sfnt_off0001288a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1288A 16204 bytes
SHA-256: e93acd332f5893643511f4cefd38969ad5c744ad1b08842a788b6be7d277dd15