Malicious PDF — malware analysis report

Static analysis result for SHA-256 713950c4ea0228e8…

MALICIOUS

PDF

74.2 KB Created: 2021-06-25 20:19:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ff8aa5ca6ac1e719d144d92332fe8ae0 SHA-1: c3d2413bfd182a22403f705e15551cc32fe1ee1d SHA-256: 713950c4ea0228e8ffc71597ee95870569ccc4642266d82ec5ca39f17ca84b0a
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery. The document body is heavily obfuscated and unreadable, providing no direct clues to its specific purpose beyond the heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://ketchas.ru/uplcv?utm_term=food+critic+how+to+become
    • https://dianthusindustrial.com/resimler/files/20062872299.pdf
    • http://npas.ru/pic/file/27459181081.pdf
    • https://fablab808.com/nbloom/fckuploads/file/53307622044.pdf
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/1607712bd74812---1563436814.pdf
    • http://shqinze.net/admin/upimg/file///29065515993.pdf
    • http://ngor2-3.com/file_media/file_image/file/28565453989.pdf
    • https://home18.ru/wp-content/plugins/super-forms/uploads/php/files/eabb7003e62a00dbf8abc5fa6d0d7a2a/79627055541.pdf
    • https://www.qbuildsoftware.com/wp-content/plugins/super-forms/uploads/php/files/1476f09402c4b127144634feb6c4ef73/36598150925.pdf
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/er0gu0cbg9dempc4om2tlqb2gd/fonowitajixovefidopepodur.pdf
    • https://szaktel.hu/uploads/file/nopipedobifosuxugilob.pdf
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/k40uunvsqhjnfi0ljl92057o40/14344312382.pdf
    • http://bhttourist.com/upload/fckimagesfile/xuboriniz.pdf
    • https://condominiobrisasdelnorte.com/userfiles/file/52735877560.pdf
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/160afd47dc7f60---44370452641.pdf
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160758cd88ddeb---66905107104.pdf
    • https://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/cb9143e91e380d6e7e9ca9449e567e37/62170699662.pdf
    • http://thongthien.vn/upload/files/godipifilekipinadevo.pdf
    • https://asaptransfers.co.uk/wp-content/plugins/super-forms/uploads/php/files/jk83hs12jlv53tdor6g0r3k7i0/25005017227.pdf
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1607739a339ed6---wimememizazevubesop.pdf
    • https://cspdental.com/wp-content/plugins/super-forms/uploads/php/files/dc42fdeffbecf77533908036c45c18fd/ketowixumaberetuxivurale.pdf
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f0bce7c4db---62366288446.pdf
    • https://thehideawayresortpattaya.com/userfiles/files/vefuzitisidikej.pdf
    • http://physiotherapy-warwickshire.com/user_file/file/xoropuliwiturodiriz.pdf
    • http://lushexperiences.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081b34d1589a---kerudejulovuluferoxixu.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_off0000c63e.bin
2f001fa577328b9377d25855e063324431670acb0975cec0192eef27e59f3250
pdf-font-stream PDF embedded font (sfnt) at offset 0xC63E 10360 bytes
font_01_sfnt_off0000dda3.bin
61711003df21abf078257ed9f54eaffc6e5c9353f0925a30734a0096ac0d77be
pdf-font-stream PDF embedded font (sfnt) at offset 0xDDA3 14984 bytes
font_02_sfnt_off00010367.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10367 16792 bytes