Malicious PDF — malware analysis report

Static analysis result for SHA-256 983c52d501480245…

MALICIOUS

PDF

67.3 KB Created: 2021-05-27 16:27:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: eee8045fcf4d8af20f733a435cde3530 SHA-1: 68654777fffeffea703dfe1daa0cc811e32a4fc7 SHA-256: 983c52d5014802451d43c5c19bc21d1e8fba22e42cc795a1bc6f4e1a38324fdd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links to external websites, many of which are hosted on compromised WordPress sites using formcraft or super-forms plugins. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery. The document body, though heavily obfuscated, suggests a lure related to 'test questions and answers'. No scripts were extracted, but the heuristic firings point to a link farm designed to redirect users to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/1606c79708af00---zipanaloneselepak.pdf In PDF document text
    • http://alnadaoil.com/userfiles/file/11347290015.pdfIn PDF document text
    • https://assurancemauricie.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072a28d7688c---zapijosuloxitexiji.pdfIn PDF document text
    • https://www.indee-r.fr/wp-content/plugins/super-forms/uploads/php/files/6ba0e0b9de5b545856f272c7f5b138a4/mavibovuserexonolifojiju.pdfIn PDF document text
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072d4df3eda4---zejabemuf.pdfIn PDF document text
    • http://musorcentrum.hu/files/article/file/4647619312.pdfIn PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/ghc5ahu9umu5adtn4k09m5b249/rarowapepejomareweminam.pdfIn PDF document text
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/cb9b17abbbf17c4686d6e81957e3d81e/1010243476.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/1608498ea87fd9---witubavepip.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606d28466ccbc---35640498843.pdfIn PDF document text
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/16083476d545d2---85472921455.pdfIn PDF document text
    • https://yingzhaoliuart.com/upload/file/97396250389.pdfIn PDF document text
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c0a98eaf78---rojivezupaxewir.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/16084d59296b78---xivowogazis.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/bc75f7869ff88e5e64cb7e33df95ecad/3401472831.pdfIn PDF document text
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608416aa6a97d---musutetakoxufufu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=the+miracle+worker+test+questions+and+answersPDF link annotation
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cb89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB89 5408 bytes
SHA-256: 1d0b5993aa5dbb55e3f33e087b10d67092ce30c9a2e67d00cf4863af36757767
font_01_sfnt_off0000ddcb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDCB 9980 bytes
SHA-256: 0f68c41b58bf1a1ed29f5e03d82147478fea76dd4ed3077b1c995fb49d47e992