Malicious PDF — malware analysis report

Static analysis result for SHA-256 851e293dd9a30aad…

MALICIOUS

PDF

68.2 KB Created: 2021-09-24 16:15:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: fc37c3cb66f9ce607b2c207b096d96cb SHA-1: 8eebc3f9df679e3d92cd4cfbfc1d3681b0ff5169 SHA-256: 851e293dd9a30aad21e4bf8427c28992d86491658d5ef97f867b5159ae817f6f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Numerous external URLs were extracted, many of which are hosted on disposable domains or compromised CMS upload storage, indicating a link farm designed to redirect users to potentially malicious content. The presence of 'utm_term' parameters suggests an attempt to track user engagement with these lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 https://chcial.ru/uplcv?utm_term=king+kong+android+game PDF link annotation
    • http://galerie45.com/userfiles/file/rezalojam.pdfIn PDF document text
    • https://bakotech.at/uploads/ckeditor/files/gedulejefakuj.pdfIn PDF document text
    • http://chinawin-consult.com/userfiles/69313604264.pdfIn PDF document text
    • https://www.shipgo17.com/plugin/ckeditor/ckfinder/userfiles/files/56302688799.pdfIn PDF document text
    • https://pnp-studio.com/fckeditorfiles/file/90222793890.pdfIn PDF document text
    • http://frezerovka.by/images/fxeditor/file/305712795.pdfIn PDF document text
    • https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b5d5cf0a92---xutarer.pdfIn PDF document text
    • http://goksirkrupskimlyn.pl/img/upload/files/duvogemokugozizaxo.pdfIn PDF document text
    • http://visusmarble.com/images_upload/files/nejejexinejimefenamit.pdfIn PDF document text
    • https://thietbixanh.net/uploads/files/52582679330.pdfIn PDF document text
    • https://shinyjewellers.com/wp-content/plugins/super-forms/uploads/php/files/edubr9u6mdc8llfjk7et9amrsc/nejurixutole.pdfIn PDF document text
    • https://minipowerpack.net/upload/files/99765122333.pdfIn PDF document text
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613335bc243c9---70617797014.pdfIn PDF document text
    • http://dpkwi.org/userfiles/files/22472881612.pdfIn PDF document text
    • http://merlegdoktor.hu/tmp/jiwopegikerolofuki.pdfIn PDF document text
    • https://bientannamhuy.com/wp-content/uploads/files/zajibokef.pdfIn PDF document text
    • http://tmkb.org.tr/ckfinder/userfiles/files/todugofodutagobozoko.pdfIn PDF document text
    • http://hiniceshine.com/upload/fewetajadamezuzuvili.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613cd73989401---fovugirulurum.pdfIn PDF document text
    • http://nhasachconggiao.com/luutru/files/44145699866.pdfIn PDF document text
    • http://cassotech.nl/site/data/ws/files/damorilujolaxe.pdfIn PDF document text
    • http://safetyassessmentsolutions.co.uk/ckfinder/userfiles/files/85295816857.pdfIn PDF document text
    • https://ashleymongolia.mn/uploads/files/91208287660.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_off0000ae11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE11 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c628.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC628 10360 bytes
SHA-256: e9a8045fe8532857c1b66409da4d7cc19421fd8cdc13ef5e930b57a2089ac0e3
font_02_sfnt_off0000dd46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD46 14988 bytes
SHA-256: 9f09d17ed4f78c2a01ddf3fac4e79fcc012f681752e5c4484903c36b83190652