Malicious PDF — malware analysis report

Static analysis result for SHA-256 57556a380c998b48…

MALICIOUS

PDF

90.1 KB Created: 2021-10-08 12:06:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 8aaa6aa35788ee671840159912cdbcab SHA-1: 62226f70bbeeede79ab17543e27f067dd21ba076 SHA-256: 57556a380c998b4844aa4a7f1dbd753391ee6c0f54d648a0ecee6c024ef40755
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to potentially malicious PDF files hosted on disposable domains. While no scripts were explicitly extracted, the PDF structure and the nature of the embedded links suggest an attempt to redirect users to malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://oilbasaro.com/web/images/ckfinder/files/20211006100811.pdf In PDF document text
    • http://uteambio.com/upload/files/38451319189.pdfIn PDF document text
    • https://hohsingfiber.com/ufiles/files/makozekapurej.pdfIn PDF document text
    • http://www.verneteco.com/ckfinder/userfiles/files/4515934769.pdfIn PDF document text
    • https://www.vconsole.com/ckfinder/files/95257820179.pdfIn PDF document text
    • https://bepcongnghiepphuchung.vn/userfiles/file/wobebizurox.pdfIn PDF document text
    • https://terlickodds.cz/www/www/fckphotos/file/valenef.pdfIn PDF document text
    • http://lamorenj.com/userfiles/file/fadosob.pdfIn PDF document text
    • http://toyotacri.com/userfiles/files/xojamuwosusaz.pdfIn PDF document text
    • http://grapes4u.ca/sites/all/sites/grapes4u.ca/files/movojakinotukimibalap.pdfIn PDF document text
    • http://kaizenlife.com/ckfinder/userfiles/files/rudazofiwa.pdfIn PDF document text
    • https://exam12.menapoint.com/app/webroot/upload/files/71946176033.pdfIn PDF document text
    • http://nwatchonline.org/userfiles/file/ziwuni.pdfIn PDF document text
    • http://xprchemical.com/upload/files/94097724758.pdfIn PDF document text
    • http://yameitecl.com/ckfinder/userfiles/files/20210923_164448.pdfIn PDF document text
    • https://geelaboba.dswip.com/ci/userfiles/files/91107230402.pdfIn PDF document text
    • http://studioarchoggianiepartners.it/userfiles/files/revuzubimep.pdfIn PDF document text
    • http://zjbfjt.com/upload/files/jiwogoluvol.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613b0441b02a4---datoninufetimojigumago.pdfIn PDF document text
    • http://wangnatheater.bpi.ac.th/ckfinder/userfiles/files/xadebulo.pdfIn PDF document text
    • http://www.pantonerestauri.com/ckfinder/userfiles/files/vumujatowafoluwaxadomatej.pdfIn PDF document text
    • https://ostrichtours.com/ckfinder/userfiles/files/99124518544.pdfIn PDF document text
    • https://pmrmhss.com/userfiles/file/5851032172.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=the+four+seasons+of+marriage+gary+chapman+pdfPDF 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_off0000f79a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF79A 18852 bytes
SHA-256: 789cdaa47d57ac1cba480e41d2b8eb8046688c83acec7ca78c39470623412a16
font_01_sfnt_off00012893.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12893 11100 bytes
SHA-256: 30e0343829bd5e93e462bfee4732f8f150aed83f04a071f7907ea11a6f262054
font_02_sfnt_off0001421b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1421B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1