Malicious PDF — malware analysis report

Static analysis result for SHA-256 139d63d7312e3bc0…

MALICIOUS

PDF

79.6 KB Created: 2021-09-17 22:50:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f50fe8c802b2a2f738072d0154a09836 SHA-1: 7ca6b15489a01d81d68b6c00712abf0b41d3b34f SHA-256: 139d63d7312e3bc0510a32875531997f21ca1918a82ef8e8a79f5a97efd5e007
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external URIs and is structured as a link farm, with many links pointing to disposable hosting or compromised CMS upload directories. The presence of embedded URLs and the overall structure suggest an attempt to lure users to malicious sites, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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
  • 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://crewmak.ru/uplcv?utm_term=sao+season+1+dub
    • http://pepinieres-soupe.com/userfiles/file/88771712789.pdf
    • https://prolocolidodisavio.org/ckfinder/userfiles/files/19840126590.pdf
    • https://upaspor.com/resimler/files/98037472564.pdf
    • http://mazdooradda.com/userfiles/file/64919000838.pdf
    • https://ahl2005.com/ckfinder/userfiles/files/tewilasakewapujibujetitov.pdf
    • http://csc020.com/userfiles/file/20210906144619_5ddex3.pdf
    • https://eventpro-kontraktorpameran.com/uploaded/files/61837000267.pdf
    • http://travelcenterpuntos.com/campannas/file/33523645711.pdf
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134405f24bae---xulalikodimujalunixomupu.pdf
    • http://a2kat.ru/userfiles/file/bakopupelanu.pdf
    • http://abarappresentanze.it/userfiles/files/24382152457.pdf
    • http://merrygoldholidays.com/ckfinder/userfiles/files/53020215462.pdf
    • http://esrafisek.com/images_upload/files/gugimikufozigoneki.pdf
    • http://gazdalkodjokosan.hu/img/userfiles/file/44824110112.pdf
    • http://christmaslandint.com/userfiles/57739828576.pdf
    • http://a1-automotivegroup.com/upload/files/65021705282.pdf
    • http://gruppocinofilomarsalese.com/userfiles/files/dumomamanuponeveter.pdf
    • https://mintowncoffee.net/uploads/images/files/sokodesovogowil.pdf
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/161360236195ba---64444393906.pdf
    • https://vayamcs.com/content_files/files/36625266015.pdf
    • https://webaprint.be/img/file/17195009821.pdf
    • http://szybkieprawko.pl/szybkieprawko.pl/user/admin/fck/file/79463461937.pdf
    • https://pielinks.com/UserFiles/file/xaruxenewenobomawavojamup.pdf
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/161448e529d707---60125701970.pdf
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/73925336afc47cbcc2905f8d6c441df1/zigibaxemepunaxawazife.pdf
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a73e2d3cc7---11194054051.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c7d3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC7D3 16792 bytes
font_01_sfnt_off0000dfe5.bin
1c65735f132839f3fe100f26c46b46c5e0e7285d27d7e6131c5da333339bd76f
pdf-font-stream PDF embedded font (sfnt) at offset 0xDFE5 21960 bytes
font_02_sfnt_off0001192d.bin
26f6256f59ee287aaa3652950a9fb8f270cf120eece9c8c70a36a213ffbaccb1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1192D 10272 bytes