Malicious PDF — malware analysis report

Static analysis result for SHA-256 f23cc39bb249963f…

MALICIOUS

PDF

72.2 KB Created: 2021-09-24 15:17:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: d784b9b66c9ff638545028424745d9a4 SHA-1: 88db7cf8eed06c79c3290cb658619f7aadba1f75 SHA-256: f23cc39bb249963f9a16c0070ccbcd385351c4f42aafd39daa3dffd8ec6853a2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URIs and is identified as a link farm, with several pointing to compromised WordPress uploads or disposable hosting. The primary lure appears to be disguised as a game download, directing users to potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://allytemp.ru/uplcv?utm_term=wr3d+20+game+download PDF link annotation
    • http://xn--80aikni6a0b.xn--p1ai/images/file/72802872211.pdfIn PDF document text
    • http://ljjxmining.com/uploadfile/file///2021091316014062.pdfIn PDF document text
    • http://secureyun.cn/uploadfile/file///2021092403522830.pdfIn PDF document text
    • http://gwardiajuvenia.pl/zdjecia/fck/file/furegusakul.pdfIn PDF document text
    • http://soc-in.com/data/media/files/nudilat.pdfIn PDF document text
    • http://paillasse.hu/userfiles/file/96942967700.pdfIn PDF document text
    • http://www.halpellet.hu/userfiles/files/90991593256.pdfIn PDF document text
    • http://giayviettri.com/img-ftec/files/dekazefamofometaxoxar.pdfIn PDF document text
    • http://oralrem.kz/ckfinder/userfiles/files/64431313456.pdfIn PDF document text
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/16132d3d1928e3---xanixuwunezadikonake.pdfIn PDF document text
    • https://refakatci.net/userfiles/file/47306839285.pdfIn PDF document text
    • http://rdmsrl.it/userfiles/files/12482500154.pdfIn PDF document text
    • http://cgmorenanews.com.br/ckfinder/userfiles/files/gufira.pdfIn PDF document text
    • http://hflbdq.com/uploads/file/080223063131.pdfIn PDF document text
    • https://samsungdvmklima.com/upload/ckfinder/files/subobawibavufogawasamu.pdfIn PDF document text
    • http://yule-sign.com/upload/editor/file/20210918183237.pdfIn PDF document text
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e37f44c3de---82883228080.pdfIn PDF document text
    • http://hkxhjfc.ltd/uploads/files/20210922192400.pdfIn PDF document text
    • https://szpital-sulecin.pl/images/fckfiles/file/16780023933.pdfIn PDF document text
    • https://samsungdvmklima.com/upload/ckfinder/files/wizexuvewawezozorosese.pdfIn PDF document text
    • http://gzwep.com/img/file/202192223246.pdfIn PDF document text
    • http://tomasmrazek.cz/userfiles/file/76689526930.pdfIn PDF document text
    • http://autowagon.it/userfiles/files/45877871282.pdfIn PDF document text
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614167adcd7f8---pawotajonawakokidiruvu.pdfIn PDF document text
    • https://vilnius.cvzona.lt/resources/img/files/vubexafunasetivoludi.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_off0000b505.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB505 17724 bytes
SHA-256: f21ad1571819aca11977ba00772586c8ae7dc757990086bf0bb6d972cfba9799
font_01_sfnt_off0000e24f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE24F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fa66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA66 10728 bytes
SHA-256: 6db7871b408a83c8339a0f2bc9495e1b871810ebab485d7930dd397f0cf7c198