Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8e388c9279fbcad…

MALICIOUS

PDF

123.0 KB Created: 2021-06-29 02:57:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9a9b16a4c2ccd7b19255b70530dd21ba SHA-1: 909ff6757bab6421031df033b9ea20c525fe29a7 SHA-256: b8e388c9279fbcadad02f04744bb74dd24b8aec8143479240acbd025a16ff492
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous external URIs and is flagged as a link farm pointing to compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to redirect users to phishing or malware distribution sites. The document body is unreadable, but the heuristic findings are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9936

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://laborke.ru/uplcv?utm_term=one+micro+coulomb
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b25d47ae3cb---42173588543.pdf
    • https://greshamgilessalon.com/wp-content/plugins/super-forms/uploads/php/files/84b77a76cfd8befbc476692ba554b656/28444381979.pdf
    • https://senzedigicraft.com/wp-content/plugins/super-forms/uploads/php/files/1046b3364e3c2450cec0cbc30d5e3de5/51144421384.pdf
    • https://sitebyside.ru/wp-content/plugins/super-forms/uploads/php/files/babb39b8f87afbf42d43bcc5cb6ca6d5/luzusevoxojewujagiju.pdf
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c037135171c---vigadoti.pdf
    • https://evenimentecastel.ro/wp-content/plugins/super-forms/uploads/php/files/1ro6ejj02mret5nc4eqooavipt/93716481793.pdf
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/a736ebba3c9d2d04ea577a609f1c6c53/80958280426.pdf
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b8081a4ebfc---82756062874.pdf
    • http://www.communityheroesproject.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b010f1e3853---balenuzu.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089fab695fbb---sudopa.pdf
    • http://ehsclassof64.com/clients/b/bf/bfa5c4411462ceee4a19e543862d902c/File/xiviterenipujug.pdf
    • https://atlanthealth.com/wp-content/plugins/super-forms/uploads/php/files/8c5487b23c4b0e159b452029dddd38a8/rovuda.pdf
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/f8fada742679e8c99c4971575e2b40c7/73746023831.pdf
    • http://el-master.ru/userfiles/file/93959729135.pdf
    • http://cn-noah.com/uploadfile/file/pisopenavifokomodizax.pdf
    • http://hoanggiaphatland.com/uploads/image/files/gafexudisikezirebijeduwul.pdf
    • http://zpb-maciejewski.pl/upload/fck/file/72080989054.pdf
    • http://musiclivemarsala.com/userfiles/files/4722328834.pdf
    • http://www.everhouse.lt/wp-content/plugins/formcraft/file-upload/server/content/files/1609e0575c386e---51576750799.pdf
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608d5c8cca547---futedijo.pdf
    • http://assushop.com/userfiles/assushop.com/file/vawevujoge.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5e6c82cb41---29281637274.pdf
    • http://timelessmebel.ru/wp-content/plugins/super-forms/uploads/php/files/6291c9efcfbe184708e6d92815ddb25d/mobexotuviwerotaxilidetuf.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_off00017d6b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x17D6B 16792 bytes
font_01_sfnt_off00019582.bin
f52bf764ee760e32855502abfd28dee9b4eddbe78d494290467f2370ecbbd582
pdf-font-stream PDF embedded font (sfnt) at offset 0x19582 10228 bytes
font_02_sfnt_off0001ac5c.bin
5b8ba415decfe9d2b6ea331f86756cc124b8294b7bffadea04fbb29c6f6dbca7
pdf-font-stream PDF embedded font (sfnt) at offset 0x1AC5C 19616 bytes