Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b878a44a4740617…

MALICIOUS

PDF

98.5 KB Created: 2021-08-23 02:01:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 93faa6c686e56d05f40c5a47fc0030da SHA-1: f26cf75222ed8f99a1b3a6f2ccb896c403185c55 SHA-256: 7b878a44a4740617ef94362181baeebb978181cf948adb4cc34bc0027d4cebdc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

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 pointing to numerous compromised WordPress uploads and disposable hosting sites, suggesting it's used to distribute malicious content or phish users. The embedded URLs, such as 'https://laborke.ru/uplcv?utm_term=asientos+contables+ejercicios+resueltos+pdf+m%C3%A9xico', are likely part of this distribution network.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://laborke.ru/uplcv?utm_term=asientos+contables+ejercicios+resueltos+pdf+m%C3%A9xico PDF link annotation
    • https://laps.pl/userfiles/file/zefanogilawazunu.pdfIn PDF document text
    • https://classicandcamper.co.uk/wp-content/plugins/super-forms/uploads/php/files/jf3ei4es6dnpqhtj3in0j2cjq0/26378099641.pdfIn PDF document text
    • http://mengnuanua.com/app/webroot/files/files/73166107387.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16075901f3176d---dikiweporanobidagosor.pdfIn PDF document text
    • https://abhimaninteriors.com/ckfinder/userfiles/files/mipurajumadusos.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16121344e0e67a---nowaralofagu.pdfIn PDF document text
    • http://riph.pl/userfiles/file/pikobamasabomabifutuf.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/togumodenatawobu.pdfIn PDF document text
    • http://amexeuro.com/an3_Uploads/file/mugazorelinofob.pdfIn PDF document text
    • https://plumcourse.com/wp-content/plugins/super-forms/uploads/php/files/c608a13f99010816577b98bff9d19b3b/sifar.pdfIn PDF document text
    • http://maroba-zirndorf.de/file/8882479678.pdfIn PDF document text
    • https://xn--b8qxb801j.tw/upload/files/womid.pdfIn PDF document text
    • https://trimix.bg/UserFiles/File/sezosavumamox.pdfIn PDF document text
    • http://euro-ex.com/images/blog//file/nizidozenanapufej.pdfIn PDF document text
    • https://keramnsk.ru/files/uploads/files/kusogipatif.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d228ef3fdd3---nibebegebirepu.pdfIn PDF document text
    • http://clarkhigh72.com/clients/3/34/34275c7d49a174b5f6cf03bf5966da6c/File/moxeluvupukelalitepeketof.pdfIn PDF document text
    • https://readxyz.com/wp-content/plugins/super-forms/uploads/php/files/982f77c8ec3b3c071c17d6a9be62ee12/zimomifuxanidima.pdfIn PDF document text
    • https://torbay.ru/images/uploads/file/13529485345.pdfIn PDF document text
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae580804a62---38256399240.pdfIn PDF document text
    • https://service-panev.com/userfiles/dixawegoraxosazevarulu.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_off00011514.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11514 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012d2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D2B 11388 bytes
SHA-256: 6ddefcd1bed73f98551ce8e7c8c8a93778e1d4182ef1f7eb7974ae9f97471341
font_02_sfnt_off0001477e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1477E 19236 bytes
SHA-256: d06b33bf2fa0d242deb391ca70a072aec13b578712d5c9ec6bbe4377470a8f93

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