Malicious PDF — malware analysis report

Static analysis result for SHA-256 ad77fd8eb7ad73b5…

MALICIOUS

PDF

86.1 KB Created: 2021-07-08 05:58:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: aa156ec860b9ddb31586de8cf370dee9 SHA-1: b7d4fe8ce330b53e83e28ae44525b9d4305e3e9b SHA-256: ad77fd8eb7ad73b5a7ee50aafd36db18da96de5809f4020f4132a1344820c9a9
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate the PDF contains a link farm pointing to compromised WordPress upload storage and other disposable hosting, suggesting it's used to redirect users to malicious sites. The document body is heavily obfuscated and unreadable, further supporting a malicious purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/160e4cc6475f9d---xenativemewosigiroranalig.pdf
    • https://srilangkapools.com/contents//files/getugeme.pdf
    • https://istocdukkan.com/userfiles/files/nudadajusebemomixo.pdf
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/silo79gr5hdtadrgppkqhk7e4b/vigovaj.pdf
    • http://andreevmag.com/wp-content/plugins/super-forms/uploads/php/files/e6151d4e73ac70c2e5833d72b89cd08a/52566447981.pdf
    • http://thedewakohchang.com/image/upload/File/9796857056.pdf
    • http://quickvideo.nl/userfiles/file/83185320721.pdf
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a72115bb22a---gexadoginubo.pdf
    • https://mercerapparelss.com/userfiles/files/96754352080.pdf
    • https://flyags.com/editorResources/file///tirudiwitofebozipezem.pdf
    • http://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/24e528925e78cd1c9e9f85b83efbed9b/vafetojutasopo.pdf
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1609b39e22084a---gazuwadofopaw.pdf
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/k4sv17k814iuh91jq8g9jmqut3/dalorivagejupiteled.pdf
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ac91398258---zalazolonejaguvowax.pdf
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/f8d5787b1d28612295170b5710cf3fe4/23145097879.pdf
    • http://gzky.cn/dubeite/ckfinder/userfiles/files/20210614_210436.pdf
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c110ed6d79---98980677156.pdf
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/1d6677aac5d6eb6e7b36c624eee46617/detazegukivilu.pdf
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160b884c912887---dexefaxafepoxakezobel.pdf
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/2601eabec684c52eec21f377fd75b146/66691065670.pdf
    • https://maintogelonline.info/contents//files/fogugunomarulina.pdf
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/e7ac0dcf268014f52ccc621b7129b502/lofazuk.pdf
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b036ce7268c---bapifur.pdf
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/frrqc0jo6crsanq0scj41vl8eq/nudux.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=should+i+sleep+in+the+afternoon
    • 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_off0000ed0b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xED0B 16792 bytes
font_01_sfnt_off0001051d.bin
3c7ed635958c6bb3b6613b41d8356959b5778aa9028c334367d46d0d4a0512d4
pdf-font-stream PDF embedded font (sfnt) at offset 0x1051D 17412 bytes
font_02_sfnt_off000132b5.bin
4b82dfcfcb847051b37af68d75383b041efa0483c7d8ba396e9d7f80358c4022
pdf-font-stream PDF embedded font (sfnt) at offset 0x132B5 10768 bytes