Malicious PDF — malware analysis report

Static analysis result for SHA-256 166cb1f4a62e6f1b…

MALICIOUS

PDF

71.1 KB Created: 2021-09-25 19:52:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 2729cd3ac0eab83abe9997c667001cfd SHA-1: bfc3b466bbea9b3be37561fb8fe74e24498a2555 SHA-256: 166cb1f4a62e6f1b9f1038926ff4ce344b717bccbc3b1b4c6d21dd1094887cdf
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple disposable domains, one of which uses a raw IP address. The document body is heavily obfuscated, preventing analysis of its specific content, but the overall structure and heuristic firings strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://bikeid.net/ckfinder/userfiles/files/33728079716.pdf In PDF document text
    • http://identik.hu/editor_up/50226341203.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fdcf861118---nuresawokizizu.pdfIn PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b1ebae0470---37838770251.pdfIn PDF document text
    • http://chistogood.ru/admin/ckfinder/userfiles/files/gubeperubolunab.pdfIn PDF document text
    • http://caogenzhiben.com/filespath/files/20210922190949.pdfIn PDF document text
    • http://gewoongroen.eu/app/webroot/files/userfiles/files/99739927003.pdfIn PDF document text
    • https://zifu-tech.com/app/webroot/userfiles/files/86479187458.pdfIn PDF document text
    • http://tnhmc.com/userfiles/file/mofiwumoxofo.pdfIn PDF document text
    • http://burragebrothers.net/demo/jolie/beta/userfiles/files/99647322710.pdfIn PDF document text
    • https://idealist.ro/userfiles/file/vikeru.pdfIn PDF document text
    • https://resulgame.com/calisma2/files/uploads/retef.pdfIn PDF document text
    • https://kaskad-74.ru/images/uploads/revoxawur.pdfIn PDF document text
    • https://mvmdigital.gr/files/files/totakekezog.pdfIn PDF document text
    • http://agierresrl.it/userfiles/files/66415833964.pdfIn PDF document text
    • https://bwhe.in/ckfinder/userfiles/files/39400190743.pdfIn PDF document text
    • http://superfishinglewood.com/uploads/files/zesawujuvozob.pdfIn PDF document text
    • http://104.156.58.56/~web2inbox/wp-content/plugins/formcraft/file-upload/server/content/files/1612fa6776f04a---vekexumozudetolupivamala.pdfPDF link annotation
    • http://architettotoma.it/userfiles/files/tuzukajeluvasod.pdfIn PDF document text
    • https://lotte-ppta.net/beta/assets/file/dototomevijiziwawipif.pdfIn PDF document text
    • https://koltoztetes-szallitas-lomtalanitas.excore.hu/ckfinder/userfiles/files/61281602257.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=weather+line+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_off0000b175.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB175 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c98c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC98C 10168 bytes
SHA-256: 53654c594292d69dba2036ee2c162cc56eb34f683250fa84bf8fcfb83393c74f
font_02_sfnt_off0000e033.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE033 17944 bytes
SHA-256: 098332475957d3cd245e654dc9dfddd9bd2f15650f2b7abaf968b5a96c39390c