Malicious PDF — malware analysis report

Static analysis result for SHA-256 9528ec6f59b9cf96…

MALICIOUS

PDF

80.2 KB Created: 2021-09-10 04:10:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ed404b7c15228a04bc08661273a3f81b SHA-1: c19f807f3f583a7929f32b692ec1b06ea3c1a9bb SHA-256: 9528ec6f59b9cf960ad25c7bfe7e7ee87ed3a571825f2a9593250c452c6b6e59
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to potentially compromised or disposable domains, suggesting an attempt to lure users to malicious sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but containing embedded URIs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 http://schokozentrale.de/idata/jedoberavifol.pdf In PDF document text
    • http://qianshunqs.com/admin/upload/zajubopab.pdfIn PDF document text
    • https://tonere.shop/app/webroot/files/userfiles/files/80825949485.pdfIn PDF document text
    • http://ksiclubbiz.ksiclub.org/svnprojects/DHD/Source/images/files/bepudoxemigaroniwoxumuma.pdfIn PDF document text
    • https://loyalangkorapartment.com/userfiles/file/joduzotapu.pdfIn PDF document text
    • https://ashleymongolia.mn/uploads/files/kimurelanofalakixiwamawuw.pdfIn PDF document text
    • https://markaoyun.com/calisma2/files/uploads/satikefezizuzomuvasu.pdfIn PDF document text
    • https://loyallcanada.com/editor_files/file/xidebotarunerenusagerava.pdfIn PDF document text
    • https://takarasushimn.com/userfiles/files/xuzulivapasuwaze.pdfIn PDF document text
    • http://www.amedna.com/userfiles/files/82586971841.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613049c83f02d---42272675843.pdfIn PDF document text
    • http://daithanhnam.com/upload/files/jewutiwuforinarima.pdfIn PDF document text
    • http://ar-intl.net/wp-content/plugins/super-forms/uploads/php/files/t7sn7jmsu7hqt4pdhthj3kugn4/41940798175.pdfIn PDF document text
    • http://bftt.marketsearching.com/upload/files/71639431440.pdfIn PDF document text
    • http://bndweb.nl/upload/files/diromaju.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a90a9bc944---23299750138.pdfIn PDF document text
    • http://milkyway-vn.com/upload/files/puzofuxobozowuwaxurux.pdfIn PDF document text
    • https://marathonroller.com/userfiles/files/movomowaxezagugusin.pdfIn PDF document text
    • http://e-hematologica.pl/users/file/depejogakabususejemivodek.pdfIn PDF document text
    • https://viadagio.be/userfiles/file/422995806.pdfIn PDF document text
    • https://www.simcoerecovery.net/wp-content/plugins/super-forms/uploads/php/files/5amgfdgof09rlns7nm9b2dkrk9/seluga.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=burning+magnesium+equationPDF link annotation
    • 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_off0000d4d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4D7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ece9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECE9 17712 bytes
SHA-256: 16009120ce208bef400a1f85e9aea9a7521ea45f552d0f9952f4c7477f2c9830
font_02_sfnt_off00011b90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B90 10704 bytes
SHA-256: 75e74ec08d4c2c349c578a824af795c4344164ba9c751109034ff3ee03121503