Malicious PDF — malware analysis report

Static analysis result for SHA-256 b6f470d5a392085b…

MALICIOUS

PDF

73.8 KB Created: 2021-10-07 12:15:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 09082d125687b103a5930371eb564927 SHA-1: 645967a8fe85f671af953b40d2c29da5ba6eb138 SHA-256: b6f470d5a392085b1958c6e117cb45803df1da4cd7391eb60bea685aa5b5a49a
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier indicating a high probability of maliciousness. It contains numerous embedded URLs that form a link farm, pointing to various disposable or compromised domains. The primary purpose appears to be directing users to potentially malicious websites, likely for phishing or to download further malware, consistent with a spearphishing attachment attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://drafthe.ru/uplcv?utm_term=fibre+and+satiety
    • http://zavalinka.by/var/upload/file/45593619367.pdf
    • https://al-farh-iq.com/upload/userfiles/file/716569409.pdf
    • http://leguido.net/files/lakumejek.pdf
    • http://spamsmsgiare.com/media/ftp/file/46918731593.pdf
    • http://serviphony.com/tinymce/jscripts/tiny_mce/plugins/phpimage/phpimage/upload/images/file/dusun.pdf
    • http://vertracapital.com/uploads/files/nanatidukojizajeselivezin.pdf
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/7e3095bc193a764aa1e6ce6e4e81a41d/vajigireparavupaleje.pdf
    • https://ilonew.tasksplan.com/userfiles/files/69675524825.pdf
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/16145102ac0fc7---15519143558.pdf
    • http://china-miyaco.com/img/file/202191635459.pdf
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615c845c87273---78587117660.pdf
    • https://perfecthospital.net/FCKeditor/file/24581799254.pdf
    • https://nhaccugiare24h.com/uploads/userfiles/file/tuwukurotederotagax.pdf
    • https://kottayammedicalcollege.org/CMS/ckfinder/userfiles/files/79581100798.pdf
    • https://inarsindbari.org/uploads/66171443068.pdf
    • http://owop.challengersports.com/ckfinder/userfiles/files/24962597424.pdf
    • http://lechioutdoor.com/userfiles/file/50976161465.pdf
    • http://creationart.hu/files/file/vibuletuvunoxafel.pdf
    • http://www.espaciocultivarte.com/ckfinder/userfiles/files/88003020636.pdf
    • http://archgeo-leszno.pl/uploads/userfiles/files/2173707475.pdf
    • https://chsins.tw/uploads/files/202109251503445454.pdf
    • http://hitplus.eu/userfiles/file/43485766409.pdf
    • http://aadcnfgl.netsociality.com/upload/files/gorurav.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_off0000bd5d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBD5D 16792 bytes
font_01_sfnt_off0000d56f.bin
29f53dbb2a6ec3ab2d22432a70234291365cbea958eb0c770828d1b4c5334b73
pdf-font-stream PDF embedded font (sfnt) at offset 0xD56F 17372 bytes
font_02_sfnt_off00010293.bin
916e97b94a2a71922c012c3298fc86db8f432bf92be1d9b0516a558ee67f67c9
pdf-font-stream PDF embedded font (sfnt) at offset 0x10293 10304 bytes