Malicious PDF — malware analysis report

Static analysis result for SHA-256 a638e593a2d72c8d…

MALICIOUS

PDF

83.7 KB Created: 2021-07-01 20:35:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 51724a21836f9538a3105ce5865fd2fe SHA-1: 8753ef7d3a93b534a58b6a237809e440324033de SHA-256: a638e593a2d72c8d788253562c1b75a2a1e31cfa509baf76093450512eed23a5
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised CMS upload directories, suggesting a phishing or malware distribution attempt. The ClamAV detection and ML classifier strongly indicate malicious intent. While no scripts were extracted, the structure and URL patterns are consistent with a link farm designed to lure users to malicious sites.

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 http://esoftland.com/userfiles/file/60528378110.pdf
    • http://casier-a-bouteilles.fr/file/pufese.pdf
    • http://lapenya.cat/imgjovesnaves/file/rabomus.pdf
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608504c2b070d---givewolegoku.pdf
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/1609881cbc29c4---xoroxozinosizolisom.pdf
    • https://uleshuzataruhaz.hu/files/file/kokenotonumeguludanufo.pdf
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080cb92a7d79---14472869070.pdf
    • https://luminex.pl/upload/file/laropuditujagopakedot.pdf
    • http://catgarner.com/clients/873270/File/4742186907.pdf
    • http://cityhighclassof77.com/clients/9/9e/9ea685038b5a197d2022a69b8c6b162a/File/16229569010.pdf
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/1607e73116616f---tegujal.pdf
    • http://prosquash.by/data/19730326215.pdf
    • http://beerskiboot.com/img/upload/file/49150376467.pdf
    • http://asea-admin.com/_userfiles/file/20210508223135.pdf
    • https://vntdc.com/upload/fck/file/ditiw.pdf
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16077d146cac2a---legujixegefatetizase.pdf
    • http://pnktools-th.org/ckfinder/userfiles/files/wojexi.pdf
    • https://sipare.com.ar/wp-content/plugins/super-forms/uploads/php/files/7tk7a70ugstjorm73n5bmumv64/51027004971.pdf
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c8a4545d718---7609890845.pdf
    • https://luminex.pl/upload/file/48516942307.pdf
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/160aaadf82cec6---72793929370.pdf
    • https://nanosoft.mn/images/content/File/jedovatorom.pdf
    • https://jooli.ru/ckfinder/userfiles/files/83583822770.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=project+communication+plan+example+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_off0000e4a7.bin
61fe7b3dc2c2bd83fbfcc6552fd79e28c954b67dabe6820be0bd17778da83e3c
pdf-font-stream PDF embedded font (sfnt) at offset 0xE4A7 16816 bytes
font_01_sfnt_off0001101a.bin
4668a0677b6aed45f37b23a52fee54fd4acbcbf21822fa7fda6cb0062c60cc27
pdf-font-stream PDF embedded font (sfnt) at offset 0x1101A 10944 bytes
font_02_sfnt_off00012971.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12971 16792 bytes