Malicious PDF — malware analysis report

Static analysis result for SHA-256 83e591fe3690b86a…

MALICIOUS

PDF

85.6 KB Created: 2021-07-03 15:47:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 337971428c3f9d9c8d09dbbe83cbe608 SHA-1: b3c97ccf47979971ee4e2a25c6e10254712baa11 SHA-256: 83e591fe3690b86aeba5412fa6aa1237a1a462b5262b99902126b1cc83d634a7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress sites and other potentially malicious domains. The presence of embedded URLs and the nature of the link farm suggest an attempt to distribute phishing content or download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9970

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://synerhu.ru/uplcv?utm_term=propagating+oyster+plant
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160c4da24043f9---94883364495.pdf
    • http://coffee33.ru/archive/file/18466340985.pdf
    • https://ises.ca/phpsites/vertical_living/uploads/file/39212898446.pdf
    • https://truck-diagnostic.ru/wp-content/plugins/super-forms/uploads/php/files/4d6a9d2dc3f593db249d9e2f4de317cb/vepapurotazigop.pdf
    • https://realxenon.ru/uploads/files/neliliku.pdf
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c397c6a3651---18199438460.pdf
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607429197ec8a---23022516946.pdf
    • https://alphaveneers.co.uk/wp-content/plugins/super-forms/uploads/php/files/c84152f4b041ecf0cee038c0170e036b/55020856790.pdf
    • http://aggengr.com/uploads/CMS/file/26713849594.pdf
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/16097fc716852e---zimaf.pdf
    • https://xn----9sbccjdbca7cyaieg1a3j.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/b8ddc7cbb42be9ecca034d14bf2c17bd/biguve.pdf
    • http://files.ibiza-ferien.de/file/kobuzosopojukonuvi.pdf
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a0cb699beb4---xosavixapigelukinifemugo.pdf
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/160ad049a5d706---31700640529.pdf
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a2557a6b134---jukenin.pdf
    • https://altonika.pro/files/fck/file/13822179456.pdf
    • http://anthonyvienna.com/sites/default/files/file/zotogef.pdf
    • http://www.ambredore.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607479f44b188---40859510597.pdf
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/pikg7g6p7a9fktbgj7d3bd3kc8/kufakobipujegovaj.pdf
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c7fc12e4ab---34688094693.pdf
    • http://albatrossmrn.com/konadnew/userfiles/file/3546916149.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_off0000ee4f.bin
67f13621a14c486dfc24bdda6ea6fa0ee18d6aff706af8846ff7a17763148130
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE4F 16772 bytes
font_01_sfnt_off00011989.bin
a5ecb9bdcd4a21590e72a3add1aaec6bfaff7ac8bd71a905908aad749ea2f8d4
pdf-font-stream PDF embedded font (sfnt) at offset 0x11989 10540 bytes
font_02_sfnt_off000131b3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x131B3 16792 bytes