Malicious PDF — malware analysis report

Static analysis result for SHA-256 4bd44b83c4a3e0b5…

MALICIOUS

PDF

79.8 KB Created: 2021-09-19 02:08:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-01
MD5: c5a9f4f5f97cd4a7194895602581d81c SHA-1: 39bf06c510fa54aa2324f4867333ee48d6f9a8eb SHA-256: 4bd44b83c4a3e0b502979b7707360ee2a3f2964916ea7003d4e1a7fb04791d77
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a callback-phone (TOAD) lure. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://archism.ru/uplcv?utm_term=market+leader+upper+intermediate+workbook PDF link annotation
    • https://kheops-so.fr/ckfinder/userfiles/files/wasolol.pdfIn PDF document text
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/1614091da7fe84---92810584937.pdfIn PDF document text
    • http://nissanotogovap.vn/uploads/images/files/xeminupiliranugagom.pdfIn PDF document text
    • http://preprod.app-nomads.com/ugecam/admin/ckfinder/userfiles/files/39598878269.pdfIn PDF document text
    • https://dangeloremodeling.com/nbloom/fckuploads/file/30013229554.pdfIn PDF document text
    • http://dongtienlamnghiep.com/upload/file/56753536013.pdfIn PDF document text
    • https://flammerouge.ch/userfiles/files/fazawetimubidovudafifa.pdfIn PDF document text
    • https://www.uniqueartzz.com/wp-content/plugins/super-forms/uploads/php/files/dgvo2f66l82ghn8ru7a44augp9/38888926828.pdfIn PDF document text
    • http://thanhnienxp.com/vietkiendo/upload/file/pidimemevezabinezigo.pdfIn PDF document text
    • http://dirpub.org/editor/ckfinder/userfiles/files/28540675519.pdfIn PDF document text
    • https://siriusdynamics.com/assets/uploads/files/51760496687.pdfIn PDF document text
    • http://thainightjob.com/ckfinder/userfiles/files/wofekulafebexed.pdfIn PDF document text
    • http://terremeraude.com/userfiles/file/warakositilaradut.pdfIn PDF document text
    • https://majubesar.info/contents/files/88753405789.pdfIn PDF document text
    • http://hzeiger.com/userfiles/file/xelebezejel.pdfIn PDF document text
    • http://fence-alarm.com/userfiles/files/62824213955.pdfIn PDF document text
    • http://leeclinic.kr/userData/board/file/34706555942.pdfIn PDF document text
    • https://baigiangtoanhoc.com/upload/files/23560484848.pdfIn PDF document text
    • http://iweldbot.com/ckfinder/pho/files/65221477927.pdfIn PDF document text
    • http://farmaciacogliate.it/userfiles/files/rejaxojuvapipigutemaxo.pdfIn PDF document text
    • http://ysenb.kr/board/file/editor/file/ligubo.pdfIn PDF document text
    • http://hzxf.com/images/upload/File/fojopegekedatelitel.pdfIn PDF document text
    • http://machinegroup.ru/img/outer/files/vonafanagawab.pdfIn PDF document text
    • http://primethailand.com/ckfinder/userfiles/files/wawafarivilarar.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_off0000ced0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCED0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e6e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6E2 19288 bytes
SHA-256: d05b4b3e36123028c0c2fc7de6b698b96d9471af5389af166e102dc741ea8786
font_02_sfnt_off00011904.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11904 10796 bytes
SHA-256: 6dfab37afde433a755e9bdf922b29669bebeda290a5dfe01dfb88ac36b6a99fd