Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8f231cf321c8c73…

MALICIOUS

PDF

81.9 KB Created: 2021-09-17 19:32:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 91986bc4ad341feeed8ed6b68cad9767 SHA-1: 36a4ea6b91691328bdbb5b8c2d343ab1337e59e9 SHA-256: b8f231cf321c8c7393eb81401592b8c4ebd8ca78f2bd34b1baebe9f98e4485fe
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or malware distribution attempt. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and the large number of embedded URLs suggest the primary goal is to redirect users to potentially harmful websites. No scripts were extracted, but the presence of numerous external links points towards a phishing or content-luring attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 5

  • 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 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://queure.ru/uplcv?utm_term=resident+evil+7+android PDF link annotation
    • https://sherwoodchamber.org/ckfinder/userfiles/files/43149851555.pdfIn PDF document text
    • https://eqonetech.com/upload/userfiles/files/bexofanaparogefa.pdfIn PDF document text
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/k7fnf4mfihl0n8irnp74n95gl1/rewixunejokali.pdfIn PDF document text
    • http://gk-eventus.ru/admin/ckfinder/userfiles/files/62711097296.pdfIn PDF document text
    • https://cnc-ar.ro/files/file/64174741728.pdfIn PDF document text
    • https://sintasyapi.com/img/userfiles/file/14039503046.pdfIn PDF document text
    • http://gitimohammadilakhimpur.org/ckfinder/userfiles/files/20448144391.pdfIn PDF document text
    • https://energiadirect.pl/application/resources/ckfinder/userfiles/files/2469883016.pdfIn PDF document text
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/161406b182adef---najivesi.pdfIn PDF document text
    • http://vejwun.cz/images/86635274047.pdfIn PDF document text
    • https://grandegroup.net/files/90280817234.pdfIn PDF document text
    • http://studioguidobarbieri.it/userfiles/files/jipazezedazajorefu.pdfIn PDF document text
    • https://atputasbaze.lv/images/userfiles/files/tanawovogodefipowa.pdfIn PDF document text
    • http://xiangzhuan.tw/upload/files/53291183907.pdfIn PDF document text
    • http://kelkenaghshband.com/app/webroot/img/files/68299721453.pdfIn PDF document text
    • https://keluargamimpi.com/contents/files/gukoz.pdfIn PDF document text
    • https://sportsslife.net/upload/ckfinder/files/dinipi.pdfIn PDF document text
    • http://old.arcnet.org.tw/ckfinder/userfiles/files/vewixawonuwag.pdfIn PDF document text
    • http://hemeringen.de/ckeditor_ablage/userfiles/files/dupiv.pdfIn PDF document text
    • http://vigen12.com/userfiles/file/wemuruturenajomodeboso.pdfIn PDF document text
    • http://ukrkarta.ua/fckeditor/userfiles/file/suzubisizimufuwunipamuven.pdfIn PDF document text
    • http://njxinbell.com/upload/files/vemaxobijeb.pdfIn PDF document text
    • https://zapret-rf.org/web/img/podborky/files/59574254070.pdfIn PDF document text
    • http://zhizhencn.com/filespath/files/20210917112555.pdfIn PDF document text
    • https://siltri.com/fck_upload/file/numugifadikim.pdfIn PDF document text
    • http://pcccphucvinh.com/upload/files/45802729365.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://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_off0000ddb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDB3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f5c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5C5 17552 bytes
SHA-256: 3d508395e93bfd3484f2aa6ee4d39592354357240c63c09d941eb17682896f7d
font_02_sfnt_off000122b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122B2 10400 bytes
SHA-256: 39a11be4c9bbc5eccd1750f965b9c462eb5b9b80caff9f4b883c1cdc7b3fa508