Malicious PDF — malware analysis report

Static analysis result for SHA-256 873c0348b5a8cc85…

MALICIOUS

PDF

86.8 KB Created: 2021-09-17 07:36:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bc7c990f3c2e766eda62d33f1d526ba4 SHA-1: ad5fef08994be38732f699b8b78b024c6d50e998 SHA-256: 873c0348b5a8cc8524632cf9004047342f82f43d3619e534ca47b997facbe1e6
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to domains flagged as link farms or hosted on potentially compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, and the document body was unreadable binary data, suggesting the malicious functionality is solely reliant on the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://poulinstrapscan.com/userfiles/file/kafoziwixonafep.pdf
    • https://theipbuzz.com/images/file/17817118403.pdf
    • http://local-minicab.com/survey/userfiles/files/57025327140.pdf
    • http://chemicalengineers.ie/images/vexufimokimof.pdf
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b1cfb480c7---60593518245.pdf
    • https://betentour.com/sites/default/files/file/64594262616.pdf
    • https://matricula.arendic.cl/files/gexabumoxiwisusopot.pdf
    • https://artedelvalle.cl/gal/files/file/jitodikilisokedadu.pdf
    • http://wanyuantemple.tw/userfiles/file/34258369608.pdf
    • http://toyteepee.com/uploadfiles/file/210904234842994712l4a29f.pdf
    • http://plkorea77.com/ckupload/files/19670308792.pdf
    • http://khacvietlaser.vn/public/images_news/files/taxoxevagepi.pdf
    • https://allianztc.ro/files/file/kelinasuzimibi.pdf
    • http://debseven.net/UserFiles/File/98618300053.pdf
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/16136953e124d4---17567356575.pdf
    • http://toonesk.com/upload/40266520473.pdf
    • https://elpollopaulino.com/cenavarra_userfiles/files/rabexokazalukigumimizu.pdf
    • http://afghansolar.com/userfiles/file/butivorusenexoranolej.pdf
    • https://www.ijestr.com/ckfinder/userfiles/files/31166625372.pdf
    • http://rococosofa.com/files/files/godiwedigub.pdf
    • http://xn----dtbsgbucafmmaf.xn--p1ai/servimages/editor/files/7185077638.pdf
    • http://maremania.net/img_pagine/file/muwuzoj.pdf
    • http://jjw-led.com/userfiles/file/jamobijasafixapida.pdf
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141dd51d5561---libikufobeje.pdf
    • http://screen.by/images/file/zofanede.pdf
    • http://chochosanencino.com/uploads/files/25935308509.pdf
    • http://ntep2008.com/UserFiles/File/44437359941.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=connecting+words+list
    • 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_off0000efaa.bin
2ca39dc581d61a10e0b44c610aa4ef2a2f975e0d2b20dcf521804d7089335753
pdf-font-stream PDF embedded font (sfnt) at offset 0xEFAA 10500 bytes
font_01_sfnt_off00010785.bin
cfd2c60aff529b8759ff9f4a9efc80f3896b9cde1def640f804b2dca5af14748
pdf-font-stream PDF embedded font (sfnt) at offset 0x10785 17936 bytes
font_02_sfnt_off0001358c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1358C 16792 bytes