Malicious PDF — malware analysis report

Static analysis result for SHA-256 b83e20713d0e6ddb…

MALICIOUS

PDF

112.6 KB Created: 2021-10-06 15:03:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 1e42fbd03eff8dfaa4458b8544aa6130 SHA-1: a3285714e66626415fee7e43a3170519da533cac SHA-256: b83e20713d0e6ddb12e9862e65f67ad272dc5e5cac55279731b924f9d8970710
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF that contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or SEO spam. No scripts were extracted from this sample, but the extensive link farm suggests an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://queure.ru/uplcv?utm_term=tale+as+old+as+time+string+quartet PDF link annotation
    • http://liga-stf.ru/i/upload/files/moxejigunejadoxo.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f6c6a215d1---33761445339.pdfIn PDF document text
    • https://onsale.social-push.cc/data/fckeditor/files/nanopimifupule.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/6daf6f320a14ffec994dbabd2c0f08f1/lijexiwixopem.pdfIn PDF document text
    • https://ringid.vn/ckfinder/userfiles/files/mawimisobejere.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/161423196dd947---lawilozew.pdfIn PDF document text
    • http://inbjnews.com/data/cheditor/0603/files/nerefowegazasalibokurato.pdfIn PDF document text
    • https://tootooair.com/FileData/ckfinder/files/20210911_BE71F878E1091EC5.pdfIn PDF document text
    • http://identik.hu/editor_up/64264159582.pdfIn PDF document text
    • http://robalton.es/Albums/images/file///fejatu.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614e30224f9e7---60236922506.pdfIn PDF document text
    • http://vibrator4you.cz/UserFiles/File/kowiraritafufozefunow.pdfIn PDF document text
    • http://goozzl.com/userfiles/files/piwunaxexikowow.pdfIn PDF document text
    • http://riviera.az/userfiles/file/gisafobukogapuxojixujo.pdfIn PDF document text
    • http://centralcogtc.com/uploads/file/gipozetudojobolebosojijav.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613244cdd6346---rozarasanotalamuritemos.pdfIn PDF document text
    • http://www.77ice.com/upload/files/golufusejajiganamij.pdfIn PDF document text
    • https://absoger.bmv-communication.fr/uploads/files/40456903362.pdfIn PDF document text
    • https://12shio1.com/contents/files/60500194490.pdfIn PDF document text
    • http://homespakistan.net/magzine/uploadfiles/file/nofodorebowetezewaluti.pdfIn PDF document text
    • http://masonhn.com/d/files/dadob.pdfIn PDF document text
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/1615aff25047e9---95656677557.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_off00014e09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14E09 20824 bytes
SHA-256: 62382beb1203c0835169adf0a84a418b2215ced7356479e8d5a852cff863afd3
font_01_sfnt_off00018449.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18449 10800 bytes
SHA-256: ec99b6bc0677fc80292c2a8ab65009bba39d552a9e73526f405959108df071c2
font_02_sfnt_off00019c9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19C9C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1