Malicious PDF — malware analysis report

Static analysis result for SHA-256 4cfff5403b05100f…

MALICIOUS

PDF

81.9 KB Created: 2021-07-10 00:00:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b9aa085bc5b9f477f6a86198299d0f39 SHA-1: 4dd1669793d167999ae7a91fae05aaec4ec1eb9b SHA-256: 4cfff5403b05100fe2cb56562cccab19e3f3afe788734e690c8d2e1b1c2277b4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs pointing to compromised WordPress sites and disposable domains, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely involving exploitation of PDF vulnerabilities to redirect the user. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://synerhu.ru/uplcv?utm_term=your+cuter+than
    • https://mahae.hu/files/files/11384566242.pdf
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/cbdmprc8t8ai6a1t49ape45214/29920729068.pdf
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b485a5c072b---6711426694.pdf
    • http://propellerclubsandiego.org/uploads/files/81141335184.pdf
    • https://jokerprod.net/userfiles/file/zadonitojafubevetinil.pdf
    • http://ebiocell.com/uploadfile/file///2021052622343341.pdf
    • http://loca-granderoue-montaletang.com/ckfinder/userfiles/files/sapoju.pdf
    • http://wearebryants.com/clients/3/3b/3bb22ab34fb8fe691aabc4d0498f9caa/File/76136559502.pdf
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160838bccb97e0---52013560109.pdf
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/252f5um3dk5d9nrstkknqa2hi0/zovobujuvig.pdf
    • https://gradeagroup.com/wp-content/plugins/super-forms/uploads/php/files/0q7u7upgh20kpcnprkc8or33mt/35566433545.pdf
    • http://plkorea77.com/ckupload/files/judaxefatukukowijuzaw.pdf
    • http://txextremecarts.com/userfiles/file/takedexajexet.pdf
    • https://www.federatedlighting.com/wp-content/plugins/super-forms/uploads/php/files/9aaead0b55a37f01b78992ef2290b610/kikavatejasa.pdf
    • http://home-delighted.com/user_img/files/fadupipowiloxod.pdf
    • http://digimaap.com/wp-content/plugins/super-forms/uploads/php/files/3hb93rai8ls4ii66kctdq8eb4c/bozuxexareko.pdf
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/4dde0d67a5468251cb899f9ccd0c5fae/69550013641.pdf
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a97aefcab77---26741363964.pdf
    • https://all-stage-meditation.tw/uploads/files/60c6449e55d2b.pdf
    • http://aprendanow.com/wp-content/plugins/super-forms/uploads/php/files/53554ed8f5af345b40f543d6cf225772/berutopenimimikilar.pdf
    • http://pokemom2.com/uploads/files/wugex.pdf
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606f332d165dc---dibedox.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_off0000dc4e.bin
a81aa7bda754a56e89a0b282072ec5312b5cb06e2b949df66bdc9539c624b2d9
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC4E 18168 bytes
font_01_sfnt_off00010c14.bin
b1d7a31fa5801516f9bc838cc5d41b968f5bcda8c9c939a586b71805e27d8074
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C14 10104 bytes
font_02_sfnt_off00012299.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12299 16792 bytes