Malicious PDF — malware analysis report

Static analysis result for SHA-256 4573f6b83235e9c8…

MALICIOUS

PDF

79.9 KB Created: 2021-05-28 18:58:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-15
MD5: f58f6c5a9d23ebf1bb480fd37b7f198e SHA-1: 14e3a772ffceed95d07d7f5e3ef4a81bc4d87b2a SHA-256: 4573f6b83235e9c8e458fdb92fe8f3fdc1dd29b2f4d0538d89bb665009b5b805
126 Risk Score

Malware Insights

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

This PDF document was flagged by an ML classifier as malicious. It contains a large number of external links, many pointing to disposable hosting services, suggesting a link farm or SEO abuse tactic. One of the primary URLs extracted is 'https://resalured.ru/123?utm_term=venn+diagram+shading+worksheet+pdf', which is likely part of a phishing or scam campaign. No scripts were extracted, but the structure and URL patterns are indicative of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 5

  • 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://resalured.ru/123?utm_term=venn+diagram+shading+worksheet+pdf PDF link annotation
    • https://lesamasipedu.weebly.com/uploads/1/3/0/7/130739144/9ba70ef7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4475559/normal_60467af44835b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393035/normal_602a1e60a689f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478134/normal_601d781ddcb8e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4480149/normal_5fd9cbbb237e6.pdfIn PDF document text
    • https://kaxozugusejerob.weebly.com/uploads/1/3/1/4/131452826/a7440612529c8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4473954/normal_60616061b8bf6.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4451561/normal_5ff6683589d53.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4447465/normal_606720db7f9e6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4412606/normal_601e72c50f5c7.pdfIn PDF document text
    • https://nozigofomin.weebly.com/uploads/1/3/4/4/134481739/d1094575.pdfIn PDF document text
    • https://fajuvupo.weebly.com/uploads/1/3/5/3/135310445/6ca9e1612682.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366666/normal_6049a168dbeef.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4452846/normal_603f2b701683f.pdfIn PDF document text
    • https://femomupine.weebly.com/uploads/1/3/4/4/134458898/sojoralaw-vuxuwikizukaso.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4422659/normal_603e21794afe5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4465277/normal_605d6586dba9e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413842/normal_5fd17c82e3f3c.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/f9e8cce1-642d-4306-882f-f9b2ade833c6/45541375180.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/79343289-644b-4e55-a5e3-54bed9bd45cc/chrissy_teigen_cravings_steak_recipe.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1a928a7c-5ef8-46c5-a8a2-f1c71ff70dae/bedirojevojanipediz.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b106589f-c0a3-4cfb-b1e9-5c66af642b81/dusubusiwuwofepod.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9bb9e37c-ebe5-43d3-b0e6-871fb7918e57/factoring_the_difference_of_two_squares_and_perfect_square_trinomials_worksheet.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_off0000f9f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9F9 5544 bytes
SHA-256: 71b990ff9cc639709c97cb4fedebe6c52ffa79a5d59f2e2566146c7f5ee321dc
font_01_sfnt_off00010cc6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CC6 11008 bytes
SHA-256: e681084fc07174ff91c8453322133a8301adb78d98cefc7e9a7d2178b4a2c00a