Malicious PDF — malware analysis report

Static analysis result for SHA-256 55dec20f9fe4d97d…

MALICIOUS

PDF

88.9 KB Created: 2021-04-01 03:07:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: 5f8a428d8c042621f74e6172c5e6b92b SHA-1: 73fb003d4db3cb9cf05a091913e680878fda57a3 SHA-256: 55dec20f9fe4d97d9f5331a380e8c5a768c54f61893de378dc2015a2996389fd
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and numerous external links point towards an attempt to leverage embedded functionalities or user interaction to visit malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://druttle.ru/strik?utm_term=how+to+open+hotpoint+washing+machine+filter PDF link annotation
    • http://mamubisuk.mypressonline.com/mabuxizuga.pdfIn PDF document text
    • https://tevaxuxelajuri.weebly.com/uploads/1/3/2/7/132712575/1807080.pdfIn PDF document text
    • http://maleev.online/23817714692g2ore.pdfIn PDF document text
    • https://zevigetadafuwun.weebly.com/uploads/1/3/0/9/130969942/4693843.pdfIn PDF document text
    • https://pamuguvijokogag.weebly.com/uploads/1/3/4/8/134883264/bajaxabuzi.pdfIn PDF document text
    • http://autokenn.com/mubijekimigasevidj6dnc.pdfIn PDF document text
    • https://zozolunefa.weebly.com/uploads/1/3/5/3/135325744/2de1567f35ca3b5.pdfIn PDF document text
    • https://bofuzezuwava.weebly.com/uploads/1/3/1/6/131636972/c16aac1d6.pdfIn PDF document text
    • https://vigejudekoseja.weebly.com/uploads/1/3/4/5/134518300/xozimi-tixowo.pdfIn PDF document text
    • https://cdn.sqhk.co/datawafag/jfghjiX/86312222818.pdfIn PDF document text
    • http://keepxufi.space/how_many_calories_are_in_a_krispy_kreme_donutswkyzk.pdfIn PDF document text
    • http://kernig.store/281417003868v1i1.pdfIn PDF document text
    • http://trelon.fun/22947785842c6mpr.pdfIn PDF document text
    • https://cdn.sqhk.co/baluwofuk/gghe7hg/how_to_play_minigames_minecraft_ps4.pdfIn PDF document text
    • https://muxavitegujun.weebly.com/uploads/1/3/1/6/131637584/xemoditibelu_kajoki_wajunofepokabot_lazozuvo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/libeganot/motionless_in_white_disguise_song.pdfIn PDF document text
    • http://zakexukosogu.atwebpages.com/nozekerotedekabife.pdfIn PDF document text
    • https://s3.amazonaws.com/sewamos/person_who_cant_stop_hiccupping.pdfIn PDF document text
    • https://s3.amazonaws.com/zakunafu/85860151653.pdfIn PDF document text
    • https://s3.amazonaws.com/megulu/72629433435.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_off00010924.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10924 5480 bytes
SHA-256: e62a5f0b866dc131e07528432e615295ba480793922870b913a6fd39eda1b6d7
font_01_sfnt_off00011bb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BB6 10840 bytes
SHA-256: b7ee398d477b4f867faa4afec8d7b3f8c9ef330467b47a7e7829a73fcf8ef461
font_02_sfnt_off000140ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x140AD 16148 bytes
SHA-256: 333c6b7950143ef5b768b9d621755905cb9f9f437be433e332b6baa8edb2b5fd