Malicious PDF — malware analysis report

Static analysis result for SHA-256 1cc905b8d3055e10…

MALICIOUS

PDF

108.0 KB Created: 2021-09-06 12:00:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 44fbdbef222b0530ced14a1303c48cd7 SHA-1: 74230573c9b1a2ed52993d932ba5920d11314449 SHA-256: 1cc905b8d3055e10321425a63a269517e62b206998b1f83d266937d8282ffdbd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with multiple heuristics indicating it's a link farm hosted on compromised WordPress sites. The embedded URLs, such as 'https://laborke.ru/uplcv?utm_term=labview+student+edition+textbook+pdf+download', are designed to lure users to potentially malicious content. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://laborke.ru/uplcv?utm_term=labview+student+edition+textbook+pdf+download PDF link annotation
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d338337fbef---9452709301.pdfIn PDF document text
    • https://sipare.com.ar/wp-content/plugins/super-forms/uploads/php/files/031eqngs8b21addbgau58rcj4n/47977815011.pdfIn PDF document text
    • http://bilmatbasim.com/userfiles/file/selokezitufitutuwimifeva.pdfIn PDF document text
    • http://www.kroonzuivel.nl/ckfinder/userfiles/files/rodabazuwabomani.pdfIn PDF document text
    • http://iwilldoit.ru/uploads/files/files/xipodavupape.pdfIn PDF document text
    • http://greenbrier101.com/userimages/sifenolizurixut.pdfIn PDF document text
    • http://ladyvenus.it/userfiles/files/sexagojapivusazilufob.pdfIn PDF document text
    • http://mega-gold.com/userfiles/files/xexipidujidamijalef.pdfIn PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c3894b6c09d---67661179792.pdfIn PDF document text
    • https://vanvoorst.info/uploaded/file/juduwevufesumetugake.pdfIn PDF document text
    • http://datavincity.com/uploads/ckfinder/files/5670180392.pdfIn PDF document text
    • https://www.ijmsir.com/ckfinder/userfiles/files/kijani.pdfIn PDF document text
    • https://ideylia.fr/uploads/file/vekujet.pdfIn PDF document text
    • https://glowskincare.net/wp-content/plugins/super-forms/uploads/php/files/16bc5a50540574c17e48abc899d79005/97541083622.pdfIn PDF document text
    • http://rent2day.ca/ci2/userfiles/files/patotekinisox.pdfIn PDF document text
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/160742c6dc7559---151873338.pdfIn PDF document text
    • http://cyklo-sport-servis.cz/UserFiles/File/kanumonasiziveno.pdfIn PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/160cc0a9dd3e3f---85789095546.pdfIn PDF document text
    • https://traveltokiev.com/wp-content/plugins/super-forms/uploads/php/files/b1pqti97h803edcaujuk1gbor4/14576142348.pdfIn PDF document text
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160ae955320cea---1428674983.pdfIn PDF document text
    • https://lisacutler.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a9a191f7e8---56996248222.pdfIn PDF document text
    • http://cheers-gifts.com/userfiles/xenatojelupefatom.pdfIn PDF document text
    • http://lexprikson.com/admin/style/images/userfiles/file/38364031089.pdfIn PDF document text
    • https://gjbuyerbroker.com/userfiles/file/beruve.pdfIn PDF document text
    • http://misterholidaysanprisco.it/userfiles/files/941736539.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_off0001359d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1359D 10936 bytes
SHA-256: 42c8c61e37544c21dc037cf466adeee9eb317f8ec6ee72d4e61a177364876594
font_01_sfnt_off00014ef6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14EF6 22696 bytes
SHA-256: 2d9b1d5474b9922e9ce73e7d2ab83fc6043ae2057ab3969d4a1e3ba83f6f4258
font_02_sfnt_off00018a11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18A11 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1