Malicious PDF — malware analysis report

Static analysis result for SHA-256 32389389e133e085…

MALICIOUS

PDF

74.1 KB Created: 2021-10-10 12:48:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 16ac7b580a03a95eb2a812a5f5357e6d SHA-1: 80d06a020e6355f60be854c9f4e98bd6db8f15a3 SHA-256: 32389389e133e0854cefe9ba8eb5e4becdaebfcb62a6489ab667412d47d8f374
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as a phishing trojan. It functions as a link farm, containing numerous URLs pointing to compromised WordPress uploads and other disposable hosting, likely intended 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 serving as a container for the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 https://garglob.ru/uplcv?utm_term=how+to+merge+pdf+files+in+windows+7 PDF link annotation
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/161622e154bcfb---xikavirajolu.pdfIn PDF document text
    • http://klusjesindex.nl/images/uploads/dijitazojedosevolasala.pdfIn PDF document text
    • http://1-sanya.com/blog_images/blog_/file/6805195476.pdfIn PDF document text
    • https://sleepthai.com/piceditor/file/pefuregizokix.pdfIn PDF document text
    • https://www.emmabowman.com/wp-content/plugins/super-forms/uploads/php/files/84dc59e59968a25a7c9aa0449e3feac3/5630663191.pdfIn PDF document text
    • https://growyourmoney.in/userfiles/files/wovobisipowowasumizi.pdfIn PDF document text
    • http://hrt-foto.hu/_user/file/ziwepuwibaxaboviko.pdfIn PDF document text
    • https://jeevadhara.org/work/london/userfiles/file/96764655033.pdfIn PDF document text
    • https://smlstripedbass.com/home/rock/public_html/ckfinder/userfiles/files/4158140243.pdfIn PDF document text
    • http://carrollcountylawyers.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/jegozuxudalusominazokap.pdfIn PDF document text
    • http://onthebroadway.com/CPD/adminpanel/upload/file/febapub.pdfIn PDF document text
    • https://kfmaccounting.com/webroot/img/content/files/rubowunavim.pdfIn PDF document text
    • https://robertbah.si/files/file/laxopaliwip.pdfIn PDF document text
    • https://z87992961.com/upload/files/20211001031448.pdfIn PDF document text
    • http://princeworldwide.com/multimedia/userfiles/file/turozijemoti.pdfIn PDF document text
    • https://marljivo.hr/UserFiles/files/57570104480.pdfIn PDF document text
    • https://888nv.ru/userfiles/file/tipawavesudaxerefizu.pdfIn PDF document text
    • http://msslink.ru/userfiles/files/16647603883.pdfIn PDF document text
    • http://88cpap.com/userfiles/files/83177632394.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614194ba79323---jifoneduz.pdfIn PDF document text
    • http://conditum.nl/userfiles/file/26926777388.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/16158307e0189b---tusesesabipulofewelilegok.pdfIn PDF document text
    • http://esistore.lu/userfiles/file/62206059787.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_off0000bf66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF66 16380 bytes
SHA-256: b16471171fba50bea6f359c1e8adbc6a433f2096e4ed501634a8a0055b393d32
font_01_sfnt_off0000e996.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE996 10808 bytes
SHA-256: 0a39d33983177c927a0ef7db932942d9a405b1fe5a69f68780d43f9ab81d1c21
font_02_sfnt_off0001024a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1024A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1