Malicious PDF — malware analysis report

Static analysis result for SHA-256 53b901b0280a62fc…

MALICIOUS

PDF

73.6 KB Created: 2021-03-10 04:43:35 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 8378b9e8c6b3db87e97bb3ced0b194d3 SHA-1: 6e7761e83fc0ff34dddc4021c9084fa6e0fa599b SHA-256: 53b901b0280a62fc7fc09ceaec67a62e72d8c95a5ba920b8769c55559cbb4533
126 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. The document contains numerous embedded URLs, many pointing to disposable domains, suggesting a link farm or phishing operation. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags the document's structure as a non-clustered link farm on disposable hosting, reinforcing the malicious nature. The primary URL, 'https://golowaki.ru/strik?utm_term=how+to+become+a+registered+nurse+in+spain', is likely part of a lure to direct users to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 5

  • 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 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://golowaki.ru/strik?utm_term=how+to+become+a+registered+nurse+in+spain PDF link annotation
    • http://kogemotuju.getenjoyment.net/why_do_certain_websites_not_load_on_my_computer.pdfIn PDF document text
    • http://gedatidigog.sportsontheweb.net/how_to_use_ipod_touch_4th_generation.pdfIn PDF document text
    • http://tadugebakonuged.getenjoyment.net/pathophysiology_of_congenital_hypothyroidism.pdfIn PDF document text
    • http://zaxevef.getenjoyment.net/81264952472.pdfIn PDF document text
    • http://midunetojonawiw.mywebcommunity.org/moto_g_power_2020_user_manual.pdfIn PDF document text
    • http://fovijivil.iblogger.org/gofisopurogarim.pdfIn PDF document text
    • http://pikejofopon.mypressonline.com/how_do_i_know_what_generation_of_echo_dot_i_have.pdfIn PDF document text
    • http://jepisafidezegun.scienceontheweb.net/genie_z45_25_owners_manual.pdfIn PDF document text
    • http://xufelaketodo.getenjoyment.net/35316440024.pdfIn PDF document text
    • http://najefot.22web.org/minadirof.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://ef9935f7-a918-44a1-999f-f1d50a45e4a7.filesusr.com/ugd/b463f2_2041e37f1f9943568fbd3497083954cf.pdf?index=trueIn PDF document text
    • http://vekejuf.atwebpages.com/adobe_animate_cc_2020_release_date.pdfIn PDF document text
    • http://posikin.myartsonline.com/11537852999.pdfIn PDF document text
    • http://xirexadugimog.atwebpages.com/90779993280.pdfIn PDF document text
    • https://042e50b4-45d0-4577-915a-c14d43ab21ad.filesusr.com/ugd/18f527_ecb77dc186ae4f4287c48bb7227659ff.pdf?index=trueIn PDF document text
    • http://genividi.epizy.com/66372216775.pdfIn PDF document text
    • http://pefimubis.myartsonline.com/jawojizevavufuxevu.pdfIn PDF document text
    • http://zepizevut.atwebpages.com/pebexesurikoziwawema.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_off0000e1d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1D4 5556 bytes
SHA-256: 42490bd610dac63d4feba0c943ac51dc659a8287d7b380bb45c5b9e306b75cae
font_01_sfnt_off0000f4a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4A7 10740 bytes
SHA-256: 922d1e684ff78a7d2498188e294f51d9a7a2c7e4aaf1075226991a3639865aa8