Malicious PDF — malware analysis report

Static analysis result for SHA-256 13831609fec287ce…

MALICIOUS

PDF

70.8 KB Created: 2021-10-03 01:35:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 2705a9f5c41ce813a221bdaa632ae8d8 SHA-1: 85b305571658d0021d238a0332bce0690e77863a SHA-256: 13831609fec287ce86159d7b6f03fc9cc1a3af2ea266c1e6b6a8df382a981421
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document contains numerous links pointing to disposable domains, a common tactic for phishing and distributing malware. While no scripts were extracted, the presence of embedded URLs and the nature of the heuristics strongly suggest a phishing attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 5

  • 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.
  • 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://www.bevillelecomte.com/ckfinder/userfiles/files/kivaw.pdf In PDF document text
    • https://libertyrealestate.in/ckfinder/userfiles/files/27674455622.pdfIn PDF document text
    • http://vpecargo.com/userfiles/file/webakukamogeg.pdfIn PDF document text
    • https://zhbiotech.com/CKEdit/upload/files/37032041835.pdfIn PDF document text
    • https://pjkconstruction.ca/images/file/11527565907.pdfIn PDF document text
    • http://pietrek.com/MARCUS/files/file/nibesoz.pdfIn PDF document text
    • http://ecohort.com/userfiles/files/momobazuvebujoma.pdfIn PDF document text
    • http://www.feniuniversity.edu.bd/app/webroot/ckfinder/userfiles/files/reritiriwibizumuba.pdfIn PDF document text
    • http://ventexevent.se/uploads/file/83342939937.pdfIn PDF document text
    • https://movingalpsfoundation.ch/userfiles/file/metusupeligedij.pdfIn PDF document text
    • https://kameramuzesi.com/upload/files/29349952015.pdfIn PDF document text
    • http://auksozvynas.lt/userfiles/file/kilufedanutokufosanef.pdfIn PDF document text
    • http://scea.edu.mn/ckfinder/userfiles/files/dowezelezitupu.pdfIn PDF document text
    • http://xn--80aamwn.xn--p1ai/userfiles/file/14123929987.pdfIn PDF document text
    • http://studiopignotti.it/userfiles/files/zaxewurawakowogemenerumi.pdfIn PDF document text
    • http://bularz-auto.pl/images/userfiles/file/winiduwag.pdfIn PDF document text
    • http://ketoanantamhcm.com/uploads/files/17815900090.pdfIn PDF document text
    • http://yule-sign.com/upload/editor/file/20210927135632.pdfIn PDF document text
    • https://ocw.tw/uploads/files/rovatolozuxegozokoxewaz.pdfIn PDF document text
    • http://baheth24aqari.com/ckfinder/userfiles/files/rogalabagugerifuza.pdfIn PDF document text
    • http://metabolit-plus.ru/files/file/misuvejakomeritop.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612f3065443a7---36497082051.pdfIn PDF document text
    • http://hophungvietnam.com/app/webroot/uploads/files/68831028619.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=meaning+of+follPDF 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_off0000b2c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2C9 17384 bytes
SHA-256: d7073bd91f625ef441ad9d75d2fd21a7880f83f62ceffda7e916db095fd30aec
font_01_sfnt_off0000df87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF87 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f79e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF79E 10016 bytes
SHA-256: 1cc540ee06bdc5bb42d32ca8e267f5afd14c8916a17793d4add8209a587c39d8