Malicious PDF — malware analysis report

Static analysis result for SHA-256 24ac553e8ad15ca4…

MALICIOUS

PDF

74.5 KB Created: 2021-04-03 16:06:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d4e2d0803602878ca9bb6e7037afc2d3 SHA-1: f516c4a993d67172a1b412e77a3892992c2d793d SHA-256: 24ac553e8ad15ca48ce38cfbeb3580bb8b4e8d58901d9b2f20a02598137f7043
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by multiple engines, including ClamAV and an ML classifier. It contains a large number of external links, many of which are SEO-themed and point to PDF files, suggesting a link farm or distribution mechanism. One of the primary external URIs, 'https://gimoguvi.ru/123?utm_term=gcse+maths+online+worksheets', indicates a lure related to educational content to drive traffic to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://gimoguvi.ru/123?utm_term=gcse+maths+online+worksheets
    • http://fajujefa.getenjoyment.net/lajasedanikewotekowe.pdf
    • http://joblanc.xyz/denelexixunavoxuxutejixz.pdf
    • http://bokaxakoz.sportsontheweb.net/65162797821.pdf
    • http://kikifikoxije.mypressonline.com/70409722493.pdf
    • http://gidedaz.iblogger.org/70515881578.pdf
    • http://legrand-spb.ru/how_to_fix_water_dispenser_not_hotxdrry.pdf
    • http://hh666o.site/67870459153zn37c.pdf
    • http://medgaj.com/what_genre_is_artemis_fowlphklu.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/pululusodogi/heroes_of_the_storm_genji_guide_deutsch.pdf
    • http://bokatamekal.rf.gd/bimanual_compression_of_the_uterus_video.pdf
    • https://s3.amazonaws.com/fukezavazuj/krups_coffee_maker_cleaning_mode.pdf
    • http://sudolurimav.epizy.com/29798267051.pdf
    • https://s3.amazonaws.com/sumesawoxajew/30030965824.pdf
    • https://s3.amazonaws.com/tigovatolis/farewell_party_email_template_to_coworkers.pdf
    • https://2ffa788b-df2f-461f-b9c5-573bec542745.filesusr.com/ugd/374ce0_5265512996224204a54d5fdcc37911b1.pdf?index=true
    • https://s3.amazonaws.com/pujinit/9555918563.pdf
    • https://6f2fb29c-15f2-4b08-b525-3eb91a7f0a41.filesusr.com/ugd/c3548c_ee10305ba15f49dc99934b0fe45aa100.pdf?index=true
    • http://jenetaponolinev.rf.gd/zevuzam.pdf
    • https://s3.amazonaws.com/peveziwoguxuzam/70977848379.pdf
    • https://c18d7360-3707-4bf1-9d6f-52ba7510fa17.filesusr.com/ugd/76cb06_2a5159e816ee412da485a214249c2f0e.pdf?index=true
    • https://s3.amazonaws.com/defipedibe/nie_boska_komedia_dantego.pdf
    • https://7ed754b6-a209-4558-9281-0032c7ee8ade.filesusr.com/ugd/4329d7_eca9cb9545fb4fcb8cf314f5fcaf8027.pdf?index=true
    • https://234d5d8d-19c9-4cab-a884-dd0775662658.filesusr.com/ugd/fb7225_840b730a113f4bc98231376c39234e08.pdf?index=true
    • 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_off0000e7a3.bin
5319c05f27b4ea81239175e7e81fe7db9ec2d0eeb23f3e2f820b7d937b2625d6
pdf-font-stream PDF embedded font (sfnt) at offset 0xE7A3 5224 bytes
font_01_sfnt_off0000f950.bin
196b67bb397e416a52cf4689633d124e3ed213dbdfc7bf40c486e05b36f6c96d
pdf-font-stream PDF embedded font (sfnt) at offset 0xF950 10288 bytes