Malicious PDF — malware analysis report

Static analysis result for SHA-256 c86e737bc17ed6b0…

MALICIOUS

PDF

80.6 KB Created: 2021-03-20 09:49:15 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 73b7d040fa4387d3111b3991d1d2034c SHA-1: 21a42ca54748c24a6a2d09253d8e7cc68638f208 SHA-256: c86e737bc17ed6b0a6cf48751323e805c66dcb694c07a3f7eb15361ab21cef5e
186 Risk Score

Malware Insights

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

The PDF contains numerous external links, many hosted on disposable domains, suggesting a link farm designed to redirect users. The ClamAV detection and ML classifier strongly indicate malicious intent, specifically identified as phishing or a trojan. The document body, though heavily obfuscated, contains keywords related to a manual, aligning with the 'PDF_SEO_LINK_FARM' heuristic which points to a large number of external PDF links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://midufefew.ru/award?keyword=cnc+bending+machine+manual+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4374860/normal_601ed0c64b424.pdfIn PDF document text
    • https://getifejijepe.weebly.com/uploads/1/3/0/7/130739552/xelomogiguwesozap.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454171/normal_602c34282ff10.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379485/normal_6025ec81b2762.pdfIn PDF document text
    • https://biwasigefo.weebly.com/uploads/1/3/1/3/131398444/6589391.pdfIn PDF document text
    • http://helper-badges.com/pk_trke_dublaj_torrentle_indir19mm4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426547/normal_6010a20d4b6ce.pdfIn PDF document text
    • http://xplaintome.ru/97910951701tamrh.pdfIn PDF document text
    • http://gojavodevagajuw.mygamesonline.org/amc_8_2017_statistics.pdfIn PDF document text
    • http://f13x.xyz/the_oedipus_plays_of_sophocles_paul_roche_audiobookx1jy3.pdfIn PDF document text
    • http://savetewolixoful.iblogger.org/fopudijadosajukoti.pdfIn PDF document text
    • https://navubenawegef.weebly.com/uploads/1/3/4/3/134320789/xepaguwuligogage.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421627/normal_5fd9293592acc.pdfIn PDF document text
    • https://norumevi.weebly.com/uploads/1/3/0/9/130969469/f5a44.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4502436/normal_5feb184d9b654.pdfIn PDF document text
    • http://pexarinolal.mypressonline.com/how_to_change_date_and_time_on_timex_marathon_watch.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4407327/normal_5fff3396d652c.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://xejobutek.onlinewebshop.net/66372375646.pdfIn PDF document text
    • http://pezefaxovojole.atwebpages.com/2010_victory_vision_service_manual.pdfIn PDF document text
    • http://gezewezelatemak.epizy.com/minecraft_server_1._12._0.pdfIn PDF document text
    • http://tibamupebunod.atwebpages.com/43424008469.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
    • 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_off0000e8b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8B7 5340 bytes
SHA-256: bc6f9897fe0b9c8508c6f725371feba65146033e92ee0175384d56f7cb742858
font_01_sfnt_off0000fabb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFABB 10956 bytes
SHA-256: bde020ed10bdabf870743efa903ac3a118312674bf603b94b0ae3a81d11f18a8
font_02_sfnt_off00011fd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FD3 16164 bytes
SHA-256: c41fc46809d2260d2d1a821cef6bb00dae560fdbad380da94a93f29d012df54e