Malicious PDF — malware analysis report

Static analysis result for SHA-256 81d85cd6e5840068…

MALICIOUS

PDF

92.4 KB Created: 2021-09-22 13:44:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 507baa01749c6926363c78d1612c8ea5 SHA-1: d74b06fc26f16995adf2fddca9985724582dcf0a SHA-256: 81d85cd6e5840068a2e093c2f39017bc401728d17fc5b355f6e413e3ad9b8953
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many of which point to disposable hosting and are structured as link farms, suggesting a phishing or scam campaign. The PDF structure and embedded URIs are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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=offensive+words+that+start+with+n PDF link annotation
    • http://alvitraders.com/files/12907218678.pdfIn PDF document text
    • http://kisito.com/userfiles/file/gukotaxawumisaze.pdfIn PDF document text
    • http://uts.edu.co/portal/app/ckfinder/userfiles/files/88982931877.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-9-18/20210918180012937186.pdfIn PDF document text
    • http://apartmany.cucoriedka.sk/data/files/13693936822.pdfIn PDF document text
    • https://nulifeus.com/~nulife/userfiles/file/zibegoruzefifasem.pdfIn PDF document text
    • http://inimtrento.it/userfiles/files/wuzefuxage.pdfIn PDF document text
    • http://stonepigments.com/userfiles/file/48335762990.pdfIn PDF document text
    • https://eirai.org/editor/ckfinder/userfiles/files/lenimumuvusagolikafekesap.pdfIn PDF document text
    • https://srmhomes.com/images/bulk_images/files/67867059866.pdfIn PDF document text
    • http://veterinariomauracotti.it/userfiles/files/92110402410.pdfIn PDF document text
    • http://xn--54-dlcdkamdj4btild5b.xn--p1ai/ckfinder/userfiles/files/88831306994.pdfIn PDF document text
    • https://vinasimex.com/uploads/file/degetikolevafej.pdfIn PDF document text
    • http://www.prunay-en-yvelines.fr/ckfinder/userfiles/files/12270750362.pdfIn PDF document text
    • https://hw-power.com/uploads/ckfiles/files/6142dcd282f3b.pdfIn PDF document text
    • https://nhaccugiare24h.com/uploads/userfiles/file/91933304571.pdfIn PDF document text
    • https://groupunsur3.com/contents/files/lebid.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c91a6a107d---49556355756.pdfIn PDF document text
    • http://ned.ru/uploads/files/tuwoberozesewutexej.pdfIn PDF document text
    • https://www.dogandemir.av.tr/paketler/ckfinder/dosyalar/files/12000755101.pdfIn PDF document text
    • http://jd6618.com/jd6618/file/2021-9/file/LwpCms2021_09_10_05_54_53_8996.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612fb24b67050---gaxerukisujaragajoxanosa.pdfIn PDF document text
    • https://misbahelmudii.org/ckfinder/userfiles/files/80792253846.pdfIn PDF document text
    • https://netcsemege.hu/ckfinder/userfiles/files/guvafupubosulali.pdfIn PDF document text
    • http://hoadondientu-ptp.vn/images/ckeditor/files/97223611514.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_off000102c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102C9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011ae0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AE0 10584 bytes
SHA-256: ca4d841f3ab03261a0678cf7c317c06308c311ea12e98c4339ad0de1f436a532
font_02_sfnt_off00013316.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13316 18380 bytes
SHA-256: 007b0a8ae736c0b29f13b405aba5760a4cd147041d9e1d389badc308af2b8656

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