Malicious PDF — malware analysis report

Static analysis result for SHA-256 7f4c7fd369893878…

MALICIOUS

PDF

93.4 KB Created: 2021-06-26 03:17:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b0fa5a847aa6fbb4ef805b57a8b0a714 SHA-1: 6cb8d3c36f6b99b5be42ffaab94c5496954ef777 SHA-256: 7f4c7fd3698938786c78da2c55d77065279394bba64a4275c83cbfb9d679a253
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The presence of embedded JavaScript and numerous links to compromised WordPress upload directories strongly suggests malicious intent. The ML classifier and ClamAV detection further corroborate this, indicating the PDF is likely a phishing or malware distribution vehicle. The embedded JavaScript is likely used to facilitate the download or execution of a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/31af82dc51bc23a202cb6813a675ba0e/jinuvu.pdf
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f1c5e8bf91---jewerokedanurazufunifubir.pdf
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/160b9818946fe1---nugubakapanerijaj.pdf
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/hfpq2di3g8r0ne0aoorfc9d2eu/gawitopupab.pdf
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/l35u7oioo0u25a2b8v8nrbab47/depukegalepabefagotik.pdf
    • https://acornschoolcharleston.org/wp-content/plugins/super-forms/uploads/php/files/946b52bc76bc7001ccc18535281676c7/degamagalalukefiv.pdf
    • https://cor.org.ar/wp-content/plugins/super-forms/uploads/php/files/jo4j0kt6fth07em61t3tq9nlvt/rumerujetusopotog.pdf
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/1770c77b402a498bdb3a031337d3889e/dowavixozokexetekizejuda.pdf
    • https://i-chat.tw/js/ckfinder/userfiles/files/xuvepemigumugali.pdf
    • http://iideree.org/wp-content/plugins/formcraft/file-upload/server/content/files/160961d6be2869---24870154945.pdf
    • https://www.psalighting.com/wp-content/plugins/super-forms/uploads/php/files/024809e95107801e49ad728f2425427d/latarowuzenugimutadiguf.pdf
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082c63307643---69004408487.pdf
    • https://ecomassage.pt/wp-content/plugins/super-forms/uploads/php/files/ed5hsue46nt0ddjvfbgeuo26ve/68969423491.pdf
    • http://aeskulap24h.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c65db59ccb0---zesoras.pdf
    • https://esprimagroup.com/userfiles/file/gitavoxu.pdf
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607edc45b8d7b---nepejurobotixataki.pdf
    • https://mysmartedu.com/uploadimages/files/80561254979.pdf
    • https://hondamienbac.vn/userfiles/file/levikidupove.pdf
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160800bedb6a10---segopidofoleterawabamugus.pdf
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1609a92445f271---96492604067.pdf
    • http://vandientuchinhhang.com/upload/files/wuwozitovabizotiki.pdf
    • https://guapa2.com/admin/fck/file/93944875669.pdf
    • https://big-cash.de/wp-content/plugins/super-forms/uploads/php/files/rkictqfqg53cuf0vlrvirqenco/98838060939.pdf
    • https://gionggiacam.com/ckfinder/userfiles/files/62506496150.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=examination+of+conscience+for+moms
    • https://sharpspringwww.kinsta.cloud/wp-content/plugins/super-forms/uploads/php/files/b372dbd85d780ed8893c9feeca83fb62/vowiwusu.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_off00010b0a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B0A 16792 bytes
font_01_sfnt_off0001231c.bin
f30b91ac27f1aaaacddeb32575d6b9b09bfbfbdfffd97f182643bd0e1a2adf7d
pdf-font-stream PDF embedded font (sfnt) at offset 0x1231C 16896 bytes
font_02_sfnt_off00014e9a.bin
4c0c08dfca8f2b1a8a7284406847ab2339b607e20fdb0df1d5ad625222400513
pdf-font-stream PDF embedded font (sfnt) at offset 0x14E9A 10536 bytes