Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a4b31da6ece2578…

MALICIOUS

PDF

80.1 KB Created: 2021-09-09 02:47:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 06a887da7221c4abfeeda1ed4c9a39f8 SHA-1: 3ad4103c479d2961bbd84ca0c0910ac1e1e95d80 SHA-256: 9a4b31da6ece2578cd2f86b9fe268792bd24b806ec920d6602ebb216a41cc362
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by a machine learning classifier and ClamAV, flagging it as a phishing trojan. Static analysis revealed it functions as a link farm, with numerous embedded URLs pointing to potentially compromised websites or disposable hosting. The primary purpose appears to be redirecting users to external sites, likely for phishing or to download further malicious content.

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 https://fengshan-zhennangong.org/upload/ckfinder/files/17930402862.pdf In PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/gpg4klj53qml04e5f1h92bu033/givewufuladajozupake.pdfIn PDF document text
    • https://bangvetthuong.com/luutru/files/594316304.pdfIn PDF document text
    • https://baigiangtoanhoc.com/upload/files/vodiwijorevefitiseji.pdfIn PDF document text
    • https://idosekotthonaveresegyhaz.hu/files/files/somipif.pdfIn PDF document text
    • http://fullx.net/files/50298494597.pdfIn PDF document text
    • http://narcisse.sk/editor_uploads/files/84552287679.pdfIn PDF document text
    • https://www.vpn-solutions.com.pe/ckfinder/userfiles/files/sowoziwi.pdfIn PDF document text
    • http://axi-hohenstein.de/userfiles/file/96114902585.pdfIn PDF document text
    • http://hzyixiangchem.com/upload/files/88997481567.pdfIn PDF document text
    • https://www.hotelrestaurantmacarena.fr/ckfinder/userfiles/files/nipaxiv.pdfIn PDF document text
    • http://telecycling.org/files/file/vedufokavugus.pdfIn PDF document text
    • http://montpellier-businessplan.com/mbp/upload/images/images/upload/ckfinder/finadedi.pdfIn PDF document text
    • http://cosonhuath.com/hinhanh_fckeditor/file/pusesepusudodolozirezoxa.pdfIn PDF document text
    • http://dfwsedan.com/nbloom/fckuploads/file/zedavulinowusupuvutaben.pdfIn PDF document text
    • http://hycxchina.com/filespath/files/20210906210513.pdfIn PDF document text
    • https://xn--64-mlcufjjaii0l.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ae8d72310195dde26c768c1f444ea193/miwitedubijuwixidewep.pdfIn PDF document text
    • http://cokhihoaiduc.com/uploads/files/pilit.pdfIn PDF document text
    • http://tivatijapan.com/uploads/userfiles/file/gewizivubonariz.pdfIn PDF document text
    • http://www.libroparlatolions.it/backoffice/ckfinder/userfiles/files/fadizizefezu.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137868a65ae2---79351016473.pdfIn PDF document text
    • https://pierrelemagicien.com/userfiles/file/tevapotolivud.pdfIn PDF document text
    • http://huabulaw.com/uploadpic/2021-9/file/2021090609131073499.pdfIn PDF document text
    • http://ryouhurt.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/zobuzusowopo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=alien+live+wallpaper+androidPDF 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_off0000d64c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD64C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ee5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE5E 17340 bytes
SHA-256: 6d8b76536dfe61e0715a9518115de6de8c50a652f2c4e1c7791abc0651112dcd
font_02_sfnt_off00011b91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B91 10252 bytes
SHA-256: 5982a697779a9d85c1ed8169afa3e0fbc143f7a5611104b6d3407071e3e10d57