Malicious PDF — malware analysis report

Static analysis result for SHA-256 55fa441bb4a800f9…

MALICIOUS

PDF

82.5 KB Created: 2021-09-19 06:47:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c95a7ccab99ebd7dd5faeea5ce6e36e7 SHA-1: d1e48a71b3e059e0875a1a796efea2bc80eadc6d SHA-256: 55fa441bb4a800f93418da073e92fa8225548fd1e5afacf8186b66d1116024a5
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URLs, many of which are hosted on disposable domains and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing or malware distribution sites. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://philabc.ru/uplcv?utm_term=format+of+sending+cv+through+mail PDF link annotation
    • http://www.kickcommerce.com/userfiles/file/68791203363.pdfIn PDF document text
    • http://mmbassisiprovince.in/files/js/ckfinder/userfiles/files/92424463612.pdfIn PDF document text
    • http://georgekoldun.com/var/upload/file/madovati.pdfIn PDF document text
    • http://m-camper.ru/ckfinder/userfiles/files/xununutikugerefawu.pdfIn PDF document text
    • http://umffz21.ru/admin/ckfinder/userfiles/files/girinexebonujokofeser.pdfIn PDF document text
    • http://minisadik-margaritka.ru/admin/ckfinder/userfiles/files/49708097317.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/161302ea8ee9c9---86407414324.pdfIn PDF document text
    • https://argumentua.com/i/file/mimumoborag.pdfIn PDF document text
    • http://studioarchterreni.it/userfiles/files/69406126076.pdfIn PDF document text
    • http://rentaruedas.com/files/others/ludigotegapud.pdfIn PDF document text
    • https://kar360.com/resimler/files/70633102435.pdfIn PDF document text
    • https://efckrakow.pl/userfiles/file/57526081606.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16134643756cfc---20959791881.pdfIn PDF document text
    • http://premiumcsp.com/uploads/files/vatoguzowovinobebifozobo.pdfIn PDF document text
    • http://csa.china-led.net/static/editor/ckeditor/ckfinder/upfile/files/lijesejurukizozew.pdfIn PDF document text
    • https://littleedupark.com/ckfinder/userfiles/files/teduzebipikutofe.pdfIn PDF document text
    • http://semihkerpiccilervesupersound.com/upload/file/zuxapebafumi.pdfIn PDF document text
    • http://cjmfgx.morefriendship.com/upload/files/1418114193.pdfIn PDF document text
    • http://issaproject.com/app/views/panel/ckfinder/userfiles/files/90320389525.pdfIn PDF document text
    • https://myreply.mobi/snappshott/editor//file/3560393801.pdfIn PDF document text
    • https://shellserva.nl/docs/Image/file/ridorigusunasoxas.pdfIn PDF document text
    • https://visualmotion.nl/uploads/file/85659294392.pdfIn PDF document text
    • http://purel-biopharm.com/upload/files/ruwete.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1614642e08edd4---49003760690.pdfIn PDF document text
    • http://abwninemile.com/uploads/files/zirajIn 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_off0000df32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF32 11068 bytes
SHA-256: 6dbb4d238e3ae03de17b9a22ffe25b38301f4443060f29abebaeec8514759498
font_01_sfnt_off0000f890.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF890 16772 bytes
SHA-256: 100bedc6e31b2b8d09f196a3d29eed535f9d3cfaca8e0d13f3caf13827aca4e1
font_02_sfnt_off000123fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123FC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1