Malicious PDF — malware analysis report

Static analysis result for SHA-256 d87b320c4bff0349…

MALICIOUS

PDF

78.7 KB Created: 2021-06-09 02:52:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 3b66ae690437285f1b35138ce981f363 SHA-1: e5721d96616fb318f8670bb40983d2dfd388999f SHA-256: d87b320c4bff03493ea9e0755c25b44b158e223f9e8c4f13198c779a86c6c33b
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 hosted on disposable domains, which is characteristic of a link farm or SEO spam campaign. The document body, though heavily obfuscated, appears to reference 'Manual instrucciones termostato honeywell cm67e', suggesting a lure to disguise the malicious intent. The ClamAV detection and ML classifier strongly indicate maliciousness, likely related to phishing or malware distribution via these links.

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://krisoc.ru/pbw?utm_term=manual+instrucciones+termostato+honeywell+cm67e PDF link annotation
    • https://sizamefoz.weebly.com/uploads/1/3/2/7/132740636/fogokazi.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4381320/normal_60b4fb5edde88.pdfIn PDF document text
    • https://tebefatudu.weebly.com/uploads/1/3/4/3/134329870/62a328.pdfIn PDF document text
    • https://muxiduxipa.weebly.com/uploads/1/3/5/3/135319221/9386942.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4501495/normal_603e62f417f27.pdfIn PDF document text
    • https://xusezazidajitov.weebly.com/uploads/1/3/5/3/135325201/c3e4e4f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4372072/normal_60065875103be.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4480423/normal_6060f037544bd.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4369179/normal_5ff885862602d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470226/normal_6040a1b976d18.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368748/normal_6031357717336.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://uploads.strikinglycdn.com/files/a468400c-1824-41c6-ba8d-7e7a681ae66f/50595804293.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/35e511d3-9320-485c-87ae-0fd50dfa17da/gebak.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/43958ffa-b965-462b-8275-47029478621e/thomson_martinet_a_practical_english_grammar_exercises_2.pdfIn PDF document text
    • http://pebokuvog.pbworks.com/w/file/fetch/144502389/asi_se_dice_level_2_workbook_answers_3.8.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e9806490-8510-437b-921a-034e6049e4eb/74395146092.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ea8c479b-5c65-43ca-a354-3aa2e0acfbab/donde_quiera_estas_tu_juan_gabriel_letra.pdfIn PDF document text
    • http://pesumireg.pbworks.com/w/file/fetch/144909114/27589359476.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e6ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6EF 5356 bytes
SHA-256: 8103f1474917e87b21005ed02a8d729a4ede914289e42cf2a21576c2581b072d
font_01_sfnt_off0000f90f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF90F 11808 bytes
SHA-256: b0470aba5297a887529190b654c6638eb49270f66230a4162ca07a8aec579b39
font_02_sfnt_off00011f0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F0B 4324 bytes
SHA-256: 7f6049e5011acf0e8581793f2bc2bb947aac2929fdb77abc318b2a6155c1ef71