Malicious PDF — malware analysis report

Static analysis result for SHA-256 c39d6030c655c872…

MALICIOUS

PDF

66.0 KB Created: 2021-03-29 19:18:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e036290f39154112ae5910a2334cb8c9 SHA-1: 77652c466b978c3a9330a1ceb537533d78f82958 SHA-256: c39d6030c655c872d052d1fbbe6395957e2bd276e9ef21b91152738901c79fb1
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, with a critical heuristic identifying a 'PDF_SEO_LINK_FARM' pointing to 30 external PDFs. The document body, though heavily obfuscated, contains a search query related to filter replacement, suggesting a lure. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution via the linked URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://kuzutuzo.ru/aws?utm_term=how+to+replace+kinetico+filter
    • http://levotavo.scienceontheweb.net/63313253747.pdf
    • http://tramlaweq.online/wojutogapewudejaxirptqau.pdf
    • https://datagoso.weebly.com/uploads/1/3/4/7/134718767/xaxila.pdf
    • https://palajuwasodix.weebly.com/uploads/1/3/2/8/132815908/7854569.pdf
    • https://kokemigigumuv.weebly.com/uploads/1/3/4/0/134042371/5821110.pdf
    • http://shop-profildoors.ru/tcp_ip_model_layers_explainedm4s4q.pdf
    • https://cdn.sqhk.co/veludewozen/ji1osgf/police_radio_soundboard.pdf
    • https://cdn.sqhk.co/wituruxa/gdgehh7/fifth_edition_character_sheet_json_files.pdf
    • http://pixunune.sportsontheweb.net/how_to_install_universal_steering_wheel_control_interface.pdf
    • http://gonifarej.mywebcommunity.org/xagikokukusofi.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/sajatofubote/wiximosumubuk.pdf
    • https://s3.amazonaws.com/panokojol/11835519258.pdf
    • http://wulibazosuxib.onlinewebshop.net/le_grand_livre_de_l_astronomie.pdf
    • https://s3.amazonaws.com/wutisigila/wezupipukejenilasisuniz.pdf
    • https://s3.amazonaws.com/bisazabe/16681657537.pdf
    • https://s3.amazonaws.com/debiwelof/41273106426.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c54a.bin
0b53ced46037165735f27d8560b4d2464c61eb4c4f86320b871de1942570cdb9
pdf-font-stream PDF embedded font (sfnt) at offset 0xC54A 4948 bytes
font_01_sfnt_off0000d640.bin
5a9d8ad39ac90f80034c1a332f67a997e38ed2175ced2a9172295e1fae25daa8
pdf-font-stream PDF embedded font (sfnt) at offset 0xD640 10340 bytes