Malicious PDF — malware analysis report

Static analysis result for SHA-256 ecb91da54b23f9e6…

MALICIOUS

PDF

77.9 KB Created: 2021-03-12 12:53:46 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: dc54920e20e12253efb68c2fe80ec31e SHA-1: 7c59fa9523f4c8f0fa809104b78ef0566fbf9200 SHA-256: ecb91da54b23f9e606de0fd812eef86bdf28043f217a670c17ae614fa8fb5646
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, a common tactic for phishing or distributing further malware. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URI heuristics suggest it is designed to redirect users to malicious sites like https://vilenefex.ru/strik?utm_term=aguda+llana+o+esdr%25C3%25BAjula.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://vilenefex.ru/strik?utm_term=aguda+llana+o+esdr%25C3%25BAjula
    • https://kowuzuworos.weebly.com/uploads/1/3/2/6/132682574/8502152.pdf
    • http://jolowenifar.iblogger.org/femudolepeja.pdf
    • https://cdn-cms.f-static.net/uploads/4497697/normal_603535997ad4d.pdf
    • https://cdn.sqhk.co/terisuzuji/hfVAxjh/power_mp3_player_free_music_download_for_android.pdf
    • https://cdn.sqhk.co/zinazejoras/DWf5Qgi/tank_recon_3d_lite.pdf
    • https://cdn.sqhk.co/noviraxat/GmgcInd/tw_followers_free_followers_for_twitch_partner.pdf
    • https://cdn-cms.f-static.net/uploads/4369933/normal_603890cc8f560.pdf
    • https://cdn-cms.f-static.net/uploads/4483602/normal_5fdc83b28b297.pdf
    • https://cdn.sqhk.co/gulezepu/oghgchb/kavimesew.pdf
    • https://cdn.sqhk.co/kelulegawi/uhhbjgI/strike_gear_x_shooter_gaming_headset_review.pdf
    • https://dagaroxir.weebly.com/uploads/1/3/5/9/135973008/rakuputudex-lowugixipajojub-wulifud.pdf
    • https://cdn.sqhk.co/seponidozit/8KigghU/97583649452.pdf
    • https://static.s123-cdn-static.com/uploads/4408324/normal_5fecc70dcef99.pdf
    • https://cdn-cms.f-static.net/uploads/4391308/normal_60462705c6e9e.pdf
    • https://cdn-cms.f-static.net/uploads/4468553/normal_5fd227c68463a.pdf
    • https://static.s123-cdn-static.com/uploads/4406169/normal_5fcd606e5754a.pdf
    • https://cdn.sqhk.co/letojeka/d7iggfc/wsdot_mountain_passes_manastash.pdf
    • https://static.s123-cdn-static.com/uploads/4387821/normal_5fcf13ab2c162.pdf
    • https://libexezelidod.weebly.com/uploads/1/3/1/4/131454359/284675.pdf
    • https://cdn.sqhk.co/rejelozekazo/xugejdP/mathworksheets4kids_multiplying_integers.pdf
    • https://wutejaguruloz.weebly.com/uploads/1/3/1/8/131871665/dakokitetib_xotalu.pdf
    • https://cdn-cms.f-static.net/uploads/4453885/normal_603037d6c4f27.pdf
    • https://banatili.weebly.com/uploads/1/3/5/3/135314160/4730847.pdf
    • https://cdn-cms.f-static.net/uploads/4427295/normal_6019355b3aebf.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://burelagufepe.epizy.com/varicela_complicada_en_nios.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_off0000f062.bin
2f150991da37161cc0a6d1c9dbb96a169eda088bf9bd7c92a4833f15f4cb8660
pdf-font-stream PDF embedded font (sfnt) at offset 0xF062 5176 bytes
font_01_sfnt_off000101dc.bin
e34717de3e3a84ed65f33a0957a520fa96ba3d2bf3b08b156d98ba063a84b7e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x101DC 12276 bytes