Malicious PDF — malware analysis report

Static analysis result for SHA-256 855cdbdd4aa4c527…

MALICIOUS

PDF

81.4 KB Created: 2021-09-18 18:24:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 7227ecdd7c8132a56176678b22032ab0 SHA-1: a367601fd8acb9bb0f2a28d128b61b4d69e84e00 SHA-256: 855cdbdd4aa4c527df5fd6b8e7d93eb60d9184dd29b9a0b165592d845b4be111
126 Risk Score

Malware Insights

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

The sample is a PDF document flagged by multiple heuristics, including ClamAV and an ML classifier, as malicious. It contains numerous embedded URLs that redirect to external sites, many of which appear to be part of a link farm designed to host malicious content or phishing pages. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_URI heuristics strongly indicates a phishing or malware distribution intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://laborke.ru/uplcv?utm_term=how+to+check+if+mobile+is+rooted PDF link annotation
    • http://logiccpacma.com/ckfinder/userfiles/files/vimiza.pdfIn PDF document text
    • http://caudafotografia.com/userfiles/files/rojat.pdfIn PDF document text
    • http://sitarofindiamd.com/userfiles/file/kumagijupikom.pdfIn PDF document text
    • http://traiteur-ribot.fr/userfiles/file/70502412075.pdfIn PDF document text
    • http://www.gonouvellezelande.com/files/21765684079.pdfIn PDF document text
    • https://intersensor.ro/v2011/Files/fck_upload/file/65529248970.pdfIn PDF document text
    • http://emotionpicturesfestival.gr/userfiles/file/12761605800.pdfIn PDF document text
    • http://duz-drustvo.si/uporabnik/file/zebef.pdfIn PDF document text
    • http://www.somdattabasu.com/fckimages/file/nikerobuzadizebajuzuk.pdfIn PDF document text
    • https://nhanloc.net/userfiles/file/90002966379.pdfIn PDF document text
    • https://theloneranger.tv/clients/loneranger/ckfinder/userfiles/files/dikifivemomowimonuvidi.pdfIn PDF document text
    • http://laiyi-art.com/userfiles/file/89278337975.pdfIn PDF document text
    • http://dermalab.pl/userfiles/file/51036313412.pdfIn PDF document text
    • http://baozhaopharma.com/upload/files/99804007683.pdfIn PDF document text
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/de64fbf5844abd58a32c38013a238cea/gatezoduwutudejovazi.pdfIn PDF document text
    • http://rspon.pl/images/wyswig_images/file/xoduru.pdfIn PDF document text
    • https://totspotdaynursery.co.uk/ckfinder/userfiles/files/xiwamavego.pdfIn PDF document text
    • http://churchontherockuk.org/home/churchontherock1/public_html/userfiles/files/35437435569.pdfIn PDF document text
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/540d8c335ec15d9152edb9288b483a4f/jiboboromajiwul.pdfIn PDF document text
    • https://podiummagazinenews.com/ckfinder/userfiles/files/13077122206.pdfIn PDF document text
    • https://safrano.pl/userfiles/file/21589860570.pdfIn PDF document text
    • http://yuanhebiotech.com/upload/files/16229741929.pdfIn PDF document text
    • https://8cj2aja7-8mxb.com/contents/files/guwiwakutewadugaferos.pdfIn PDF document text
    • https://toppelletmachine.com/d/files/berozolafamivabemofi.pdfIn PDF document text
    • http://kiuruvedenlukio.fi/tiedostot/file/nesevavomatizofuvivilo.pdfIn PDF document text
    • http://poliinc.com/upload/files/vumoxelamegiku.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_off0000d8c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8C0 17996 bytes
SHA-256: da2aa5c44f7fced15370951134088fb7d4d5c8fe25904b073f5b272d21ed5334
font_01_sfnt_off00010693.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10693 10784 bytes
SHA-256: 66d54c86f533d56710cda2eae277fead71729d58e8582fe318e483a8042f073b
font_02_sfnt_off00011f65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F65 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1