Malicious PDF — malware analysis report

Static analysis result for SHA-256 773d4631e1e20be9…

MALICIOUS

PDF

87.0 KB Created: 2021-09-18 10:17:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: ca32e9c586df7484fced6b271444026e SHA-1: 08503b02485900d04f66f1de1c0f86005c781a62 SHA-256: 773d4631e1e20be937f88ffe6deecbbeb5fe375d87642af9e2e574cb0c4303e7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with numerous URLs pointing to potentially compromised websites or disposable hosting. The presence of embedded URLs and the nature of the heuristics suggest the document is designed to redirect users to external malicious sites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://smidgel.ru/uplcv?utm_term=how+to+add+timer+in+video+android PDF link annotation
    • http://studioagronomoserragiotto.eu/userfiles/files/53022218271.pdfIn PDF document text
    • https://perfecthospitals.org/ckfinder/userfiles/files/wezesopokeminevavirizu.pdfIn PDF document text
    • http://bona-agra.pl/Upload/file/99260581399.pdfIn PDF document text
    • https://oklogistic.lv/upload/file/83070284420.pdfIn PDF document text
    • https://whitepalacegrill.com/userfiles/nulilebukuzujut.pdfIn PDF document text
    • http://caminodesantiagoenmoto.com/assets/ckfinder/core/connector/php/uploads/files/ditefomifatel.pdfIn PDF document text
    • http://maudchristan.nl/ckfinder/userfiles/files/83290119243.pdfIn PDF document text
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/4bc1e6043449d88ec2904437b267586e/30511308110.pdfIn PDF document text
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142b37183366---7591400983.pdfIn PDF document text
    • http://xn--ob0bjxt9h99icicrvkksa421cwwp7hiv4d6a.com/ckfinder/userfiles/files/8809301852.pdfIn PDF document text
    • https://toscanafantastica.com/userfiles/file/69703497407.pdfIn PDF document text
    • http://prmakeup.com/Image/files/vavexew.pdfIn PDF document text
    • http://hc6999.com/userfiles/files/sotatotagujerutofuxosid.pdfIn PDF document text
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b71d6e4ac6---47887173765.pdfIn PDF document text
    • http://noahmission.org/dataroom/file/60203108367.pdfIn PDF document text
    • http://lnshiyue.com/userfiles/file/20210913052433_1461476083.pdfIn PDF document text
    • http://harc-ias.vn/Images_upload/files/84457567475.pdfIn PDF document text
    • http://christopherspubandgrille.com/userfiles/files/sazudirufutupizagijo.pdfIn PDF document text
    • https://olamare.com/img/uploaded/file/dopazinewiparimunemiluxa.pdfIn PDF document text
    • http://dnt-mayak.ru/content/File/82712779697.pdfIn PDF document text
    • http://elite-nails.pl/Upload/file/sakubonol.pdfIn PDF document text
    • http://silver.jo/ckfinder/blanc/files/kimudosabiz.pdfIn PDF document text
    • https://www.q-jin.ne.jp/ckfinder/userfiles/files/87049084650.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_off0000f08b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF08B 17908 bytes
SHA-256: 5940428cc3615293d867a7c55fcd74f3463bc1104d117a2be22c1f560705cfda
font_01_sfnt_off00011ee1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EE1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000136f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136F8 10340 bytes
SHA-256: 9f5d3e20db61be926aa784066a1499739be7bbce67269f98cf8680c0f6a8756f