Malicious PDF — malware analysis report

Static analysis result for SHA-256 b88d4f6fe139d7da…

MALICIOUS

PDF

63.9 KB Created: 2021-01-21 21:10:31 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-15
MD5: 74ff6b6bf6c88b37317ba1d28e5479eb SHA-1: 9d1be245c8ba767622ce5b61f9f30f0a655acea5 SHA-256: b88d4f6fe139d7daf3525a8ac19b073f864fb2230a00766206e379f8f15d9784
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, many pointing to disposable domains, suggesting a link farm used for phishing or malware distribution. The document body, though heavily obfuscated, appears to be a lure related to worksheets, which is consistent with the PDF_SEO_LINK_FARM heuristic.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://jottigo.ru/123?utm_term=apostrophes+for+contraction+worksheet+pdf PDF link annotation
    • https://dolojimopa.weebly.com/uploads/1/3/4/8/134887070/melexoj.pdfIn PDF document text
    • https://site-1175435.mozfiles.com/files/1175435/christmas_runner_carpet.pdfIn PDF document text
    • https://site-1175032.mozfiles.com/files/1175032/pomukufitupuzuli.pdfIn PDF document text
    • https://vifazadaza.weebly.com/uploads/1/3/4/8/134883600/xunoxozamiwu.pdfIn PDF document text
    • https://detofupupe.weebly.com/uploads/1/3/1/3/131384021/e15716897001.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4497650/normal_5fd27a7068193.pdfIn PDF document text
    • https://woluxubofij.weebly.com/uploads/1/3/1/3/131383763/vutugi_zaxidafama.pdfIn PDF document text
    • http://lajulufubugo.22web.org/60109982779.pdfIn PDF document text
    • https://kegegizexuf.weebly.com/uploads/1/3/4/0/134042356/tamaboxukunigas.pdfIn PDF document text
    • https://giloxegikejuzun.weebly.com/uploads/1/3/4/7/134712531/2078732.pdfIn PDF document text
    • https://site-1178226.mozfiles.com/files/1178226/manual_de_huawei_mate_10_pro.pdfIn PDF document text
    • https://site-1244582.mozfiles.com/files/1244582/fidic_quick_reference_guide_pink_book.pdfIn PDF document text
    • https://site-1235418.mozfiles.com/files/1235418/fijad.pdfIn PDF document text
    • http://jesiwufap.iblogger.org/wow_classic_fishing_guide_horde.pdfIn PDF document text
    • https://tatelemu.weebly.com/uploads/1/3/1/1/131164239/dibaxiw.pdfIn PDF document text
    • https://site-1173526.mozfiles.com/files/1173526/medical_bacteriology_a_practical_approach.pdfIn PDF document text
    • https://lijepaxo.weebly.com/uploads/1/3/5/3/135324298/tesuledosopajabixof.pdfIn PDF document text
    • https://site-1168218.mozfiles.com/files/1168218/fefokepajipepenilugi.pdfIn PDF document text
    • https://jowetirepenu.weebly.com/uploads/1/3/1/3/131383619/689198.pdfIn PDF document text
    • https://site-1175354.mozfiles.com/files/1175354/7541664361.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://supetok.rf.gd/best_free_video_er_website.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_off0000bc99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC99 5356 bytes
SHA-256: 53b5cc43e9d6e6aadf97676af9b5dc3cdd7448f3e50147e1f1073eecd2fc5248
font_01_sfnt_off0000cee0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEE0 10364 bytes
SHA-256: 4c22f522aaa5cd75fc1cf1c0c3f33357c1ad0648fcc75e54223235d3d68dbc63