Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4a7a365d800141a…

MALICIOUS

PDF

86.8 KB Created: 2021-04-19 02:17:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: 10dafa973801a10d521c633f50e36688 SHA-1: 6f5bb713563c534bd85f9b4cd0fa82fcf736627f SHA-256: c4a7a365d800141ac587f7171306b44010650646052e907e7613408539dbfe30
126 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO spamming operation. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the presence of numerous URLs suggests an attempt to redirect users to malicious or ad-heavy websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://druttle.ru/strik?utm_term=how+to+find+taylor+series+of+complex+function PDF link annotation
    • https://repugololenip.weebly.com/uploads/1/3/4/8/134880500/dijene.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414332/normal_600f9dc068751.pdfIn PDF document text
    • http://befujukipepejem.mygamesonline.org/nazijo.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4444123/normal_6015a5ccdded7.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4460057/normal_5fdffed8e87d2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403406/normal_606d227ebc9ff.pdfIn PDF document text
    • https://kamubopo.weebly.com/uploads/1/3/4/6/134631829/rumowazi_sajetariwitovop_nafugibiw.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387243/normal_6046b9951cb78.pdfIn PDF document text
    • http://vozobatenaw.mywebcommunity.org/sql_database_tutorial_for_beginners_free_download.pdfIn PDF document text
    • https://lejujazu.weebly.com/uploads/1/3/5/3/135337057/8860919.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://kewevagisugimuw.onlinewebshop.net/life_cycle_cost_analysis_example.pdfIn PDF document text
    • https://c83cbd6e-a134-4b49-ba12-49f24c654ad9.filesusr.com/ugd/904a8b_32c38dd046d44d96b1e882635b343c4c.pdf?index=trueIn PDF document text
    • https://6f1239e7-da96-47bf-8adb-22d47a96a9da.filesusr.com/ugd/bb5a15_35234917693f4390aa9856477c36c557.pdf?index=trueIn PDF document text
    • http://fetekovabu.onlinewebshop.net/rudram_tamil_free_download.pdfIn PDF document text
    • http://gununusaw.epizy.com/93320465999.pdfIn PDF document text
    • https://69b3109a-7cce-4514-9193-d2106d9976ab.filesusr.com/ugd/3c2969_7900135365f3491f9407dc06637a6205.pdf?index=trueIn PDF document text
    • https://229013d5-0e14-4531-be8c-43df84542e77.filesusr.com/ugd/e4a895_88f5301d5fd747e19014b82e0a35f354.pdf?index=trueIn PDF document text
    • https://176fe727-baa2-4f6f-8ab0-cddcd97ecb74.filesusr.com/ugd/45df28_cd027ddf35e54fa480e22cad49f59062.pdf?index=trueIn PDF document text
    • https://828c6a01-da61-4814-986a-f72e64f4f334.filesusr.com/ugd/cdfdba_d3a071559fad44b788f10b23c3dc4e17.pdf?index=trueIn PDF document text
    • http://xosifupevevatim.epizy.com/ragowuwoj.pdfIn PDF document text
    • https://7404da97-7fcf-4d5f-9d5f-3f8644e6773a.filesusr.com/ugd/35f767_264c4ba9a23347f18aed9b47fd9c3e8c.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fbdd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBDD 5524 bytes
SHA-256: ceb436ac2bff37060f26190764f1bd15a5eeab1e40922aa9c0d04d8da64a8ae1
font_01_sfnt_off00010eaf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EAF 11556 bytes
SHA-256: b31fbc42fdd3bc66edb8dbd708e0d5346f041d4ef0838bd8d7690af0cd47caa1
font_02_sfnt_off00013667.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13667 16092 bytes
SHA-256: 0ce4f8b47c9991bd1ed0a694d919b88134844ea7ba04d4b6a373289a8b5175c0