Malicious PDF — malware analysis report

Static analysis result for SHA-256 658f7977e5cb6736…

MALICIOUS

PDF

80.4 KB Created: 2021-09-20 02:18:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 086d562b0e300cd7c790d10332d50003 SHA-1: c197a7a9eba5fab1ed96f875e7c13d1d96746604 SHA-256: 658f7977e5cb6736c0729a2f53b6337f3be987c23be7a77e89df5b0fb3b2ed52
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document flagged by ML classifiers and ClamAV as malicious. Heuristics indicate it functions as a link farm and a callback lure, suggesting a phishing or scam attempt. While no scripts were explicitly extracted, the PDF structure and embedded URLs point towards an attempt to redirect users to malicious sites or engage them in fraudulent phone calls.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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 http://daedukgs.com/admin/fckeditor/data/file/20210919114956.pdf In PDF document text
    • http://yongqingtech.com/d/files/wixetozekerefijiredo.pdfIn PDF document text
    • http://mayingiabao.com/upload/files/ropesetot.pdfIn PDF document text
    • http://e5tbr.alruaa.com/ckeditor-ckfinder-integration/uploads/files/giradetukinomogezenopobi.pdfIn PDF document text
    • http://1day2night.com/UserFiles/file/lokutadubimas.pdfIn PDF document text
    • https://rozynoklinika.lt/userfiles/file/buxuluvukijumupareluwumal.pdfIn PDF document text
    • https://hoangphatdanang.com/uploads/image/files/segufegi.pdfIn PDF document text
    • http://ormansagszive.hu/upload/file/sesovuguvadumomorawomajis.pdfIn PDF document text
    • http://vdadanang.vn/app/webroot/assets/files/69619784242.pdfIn PDF document text
    • https://zenithoverseas.com/assets/userfiles/files/82690679950.pdfIn PDF document text
    • https://bustotoronto.com/userfiles/file/jasutazov.pdfIn PDF document text
    • http://eptesteplelek.com/uploads/file/sudazubeki.pdfIn PDF document text
    • http://ecohort.com/userfiles/files/gopiwipijekowoloxu.pdfIn PDF document text
    • http://citranco.com/users/files/salesufekuvuwexenosisi.pdfIn PDF document text
    • http://print-printonline.com/ckfinder/userfiles/files/fujupimizud.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613134672f156---27324214684.pdfIn PDF document text
    • http://carszana.com/image/upload/File/zelazonujunapumememunebed.pdfIn PDF document text
    • http://plantessentialoil.com/upload/files/26903171952.pdfIn PDF document text
    • http://sichera.eu/userfiles/files/34107412079.pdfIn PDF document text
    • http://elverum-revmatiker.no/images/file/vogolunefovazubitowuxe.pdfIn PDF document text
    • https://publicbridge.pl/userfiles/file/satukiti.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614297839a7d8---muxowasoruwetomirowas.pdfIn PDF document text
    • http://plantessentialoil.com/upload/files/35872619581.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=bank+of+india+star+token+for+android+mobilePDF 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_off0000d560.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD560 17376 bytes
SHA-256: f90ffd2cae9f29dde4ae3490e5cbb1a85cf8c598df28aeed13bf3e36253f2863
font_01_sfnt_off000102c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102C2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011ad9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AD9 10800 bytes
SHA-256: 42b79c7ce9e3243f919f4dce15ebc2933c77d8fcf6c1461aa97d3f9010f8ae17