Malicious PDF — malware analysis report

Static analysis result for SHA-256 b99c789ed6ebe247…

MALICIOUS

PDF

76.8 KB Created: 2021-03-21 07:28:02 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-17
MD5: 01afa59c6c2247a8a8d06aa15cdc6fe7 SHA-1: 1e5f86faa38f1417a61fbac8bc81b9ceeac674fb SHA-256: b99c789ed6ebe2474cf52d22f34bde879666e4eeed5099b2c36d502cade869ff
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to disposable domains and potentially malicious hosting, as indicated by the PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics. The ML classifier and ClamAV also flagged this file as malicious, specifically as a phishing or trojan variant. While no scripts were explicitly extracted, the nature of the link farm suggests an attempt to redirect users to malicious sites, potentially for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://nipisod.ru/123?utm_term=memorandum+of+understanding+template+nhs PDF link annotation
    • http://usersdeviceprotectionservice.site/why_am_i_having_so_much_normal_dischargex9nj7.pdfIn PDF document text
    • https://befugusugub.weebly.com/uploads/1/3/2/6/132683140/50d4d34da1990.pdfIn PDF document text
    • http://eagleaff.com/troy_bilt_ohv_208cc_oil_capacityc43g7.pdfIn PDF document text
    • http://tublitalia.space/define_computer_programming_and_exampleh1j7n.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4467936/normal_604ac9b0e6d0b.pdfIn PDF document text
    • https://kimimidinom.weebly.com/uploads/1/3/1/4/131453749/6751683.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476434/normal_5fe653a8a9f13.pdfIn PDF document text
    • https://mazokozofifux.weebly.com/uploads/1/3/4/3/134305155/naluxis.pdfIn PDF document text
    • http://d2-club.ru/swingline_heavy_duty_stapler_how_to_replace_staplesdvqg7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375339/normal_602417aa3158e.pdfIn PDF document text
    • https://dakaxepipuzegi.weebly.com/uploads/1/3/4/8/134869431/4696026.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370987/normal_602d5157ab658.pdfIn PDF document text
    • https://mevuponepom.weebly.com/uploads/1/3/4/8/134899748/405d86cf23c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4484356/normal_604e62626aa18.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://s3.amazonaws.com/gupawupigawono/namita_agarwal_all_bhajan.pdfIn PDF document text
    • https://s3.amazonaws.com/libosokune/4006739691.pdfIn PDF document text
    • https://s3.amazonaws.com/vavebufevodutob/ugly_sweater_contest_template.pdfIn PDF document text
    • https://3eeb541e-75be-486c-a732-b1e279b2a932.filesusr.com/ugd/eaab1c_16fa92e1e9c44b85aaa6175110b1e53f.pdf?index=trueIn PDF document text
    • https://d427386d-3434-45d9-8802-370857a594f4.filesusr.com/ugd/accd1f_ba5e0a870f52478a9119786cf3b340e7.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_off0000e112.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE112 5340 bytes
SHA-256: 3a5ba6a127b2ef38ba3ddeb284cba4be8d52425ee2aabb36fc4b61de094656c7
font_01_sfnt_off0000f30e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF30E 10824 bytes
SHA-256: 95a2b8acfb873e0e487e84cce5464215197c34e5abb0bab04acc429a05467384
font_02_sfnt_off000117e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117E3 4324 bytes
SHA-256: d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378