Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1c7975412e71cf3…

MALICIOUS

PDF

95.3 KB Created: 2021-07-24 15:53:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: fe6a477f6596f1bf305f8ccb258f375b SHA-1: bca1da5093b2f08d1653ddcb897ff4985d354eef SHA-256: a1c7975412e71cf3b1d654f936dc69e84d03931270688485fb8d8a0c4a50fe7d
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicative of a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL analysis and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 http://walker-doss.com/clients/4/45/450b4a4af5ff3f13851793278d9c7ef8/File/jifidujorarabologesaju.pdf In PDF document text
    • https://forumhrdbekasi.com/webroot/userfiles/files/87210397856.pdfIn PDF document text
    • http://peaceinsrilanka.lk/userfiles/file/76977377102.pdfIn PDF document text
    • http://sad-azov.ru/wp-content/plugins/super-forms/uploads/php/files/6fbec4beae18f8e6cadd6895a41a6db3/65208918822.pdfIn PDF document text
    • https://southtours.com/wp-content/plugins/super-forms/uploads/php/files/8fbtikk8r2q8qcqoj7odgaapmb/23546340931.pdfIn PDF document text
    • http://eros-arena.de/eros/userfiles/file/3411303375.pdfIn PDF document text
    • http://exmar.it/foto_fck/file/3203597251.pdfIn PDF document text
    • http://twfindia.in/userfiles/files/62373698324.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/q7m963i39te8h5s9vt9oaes081/45554989342.pdfIn PDF document text
    • http://coinmarketsuite.com/ckfinder/userfiles/files/13806013522.pdfIn PDF document text
    • http://www.la-rocca.pl/app/webroot/files/files/13954972807.pdfIn PDF document text
    • https://drlanda.hu/user/file/refarasazirejarekon.pdfIn PDF document text
    • http://absigorta.com/E/file/rowixenipa.pdfIn PDF document text
    • http://kaies.net/upfiles/file/67881852973.pdfIn PDF document text
    • http://wuxihemei.com/ckfinder/userfiles/files/20210621_210926.pdfIn PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/160841b21bebc1---luzozibemiwavijitizo.pdfIn PDF document text
    • https://ngonluathan.vn/images/ckeditor/files/xutovemo.pdfIn PDF document text
    • http://cainghienbinhduong.com/uploads/userfiles/file/13196023118.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d23ae285f96---dasala.pdfIn PDF document text
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/0e84803e353452906ed93af83cfd87a4/8264797515.pdfIn PDF document text
    • http://alibabashipping.com/userfiles/file/90756574240.pdfIn PDF document text
    • https://functionalmovement.gr/wp-content/plugins/super-forms/uploads/php/files/eeb8d0d5fb9d42ceaa6e2e5583014491/81614901865.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/jehnv4hf6cd0g1t5msg3f64c33/54975447806.pdfIn PDF document text
    • http://drive4smilesquebec.com/clients/f/f5/f58105ca183540932673f5bf18e62671/File/19332622037.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=general+knowledge+trivia+questions+2021PDF 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010aec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AEC 19572 bytes
SHA-256: 8e9fb16b4d078dc5fb64f27b8e1f919a23264156ff7c6e48e24303793be56e66
font_01_sfnt_off00013ccc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13CCC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000154e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x154E3 11248 bytes
SHA-256: 7208ec35c27f9e831c90fd3065c143e89d80cfbbfd208bac0fe45e2107ce2c24