Malicious PDF — malware analysis report

Static analysis result for SHA-256 4321536b7ac31629…

MALICIOUS

PDF

82.2 KB Created: 2021-09-10 06:05:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3ae5eec7a438f67a1a5fce7d4554fae9 SHA-1: 41515ced097e007755159d1a847968cef819a071 SHA-256: 4321536b7ac31629423853fab8592d4ff77928dc3bfd25bf0c6df76518a59e7a
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. It contains numerous links to external websites, many hosted on compromised CMS uploads or disposable domains, suggesting a phishing or malware distribution scheme. The PDF structure and embedded links are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://chiari-web.com/ckfinder/optimist/files/wusikurosexejezuminad.pdf
    • http://xn--zb0by3yusal20ak5lcidnwigi.com/ckfinder/userfiles/files/1630743709.pdf
    • https://behbehaniprojects.com/uploads/files/jekojipagexukepakoru.pdf
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/16138bc82ca7e2---paratekeki.pdf
    • http://gzperson.com/uploadfile/files/79999143876.pdf
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/4818ea1ca0b380127d45c415888185d0/67622830508.pdf
    • http://probeg2000.ru/files/userfiles/files/13218315420.pdf
    • http://kadh.kr/bobod/upload/file/7995065263.pdf
    • http://ikhmongol.mn/ckfinder/userfiles/files/13319710423.pdf
    • https://imapcb.org/wp-content/plugins/super-forms/uploads/php/files/7cbbb9937f553ed69df90a0cc9bdf893/bamatunojopibijup.pdf
    • http://bubb.cn/up_file/file/fonuxop.pdf
    • https://thietbivesinhsonhoa.com/webroot/img/files/divarukujir.pdf
    • http://123flower.doweb.kr/upload/files/51728976675.pdf
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/16138c44331503---51692626048.pdf
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/80072710cd7a2348028307ee10953b8a/52449492518.pdf
    • https://dusunceokulu.net/resimler/files/79804073565.pdf
    • https://parisautotravel.com/wp-content/plugins/super-forms/uploads/php/files/2nbj41n4erdbh7ntkubih21oh6/43531838732.pdf
    • https://psihodesk.ro/ckfinder/userfiles/files/29706709374.pdf
    • http://abwvictory.com/uploads/files/86561323229.pdf
    • https://novitas.ro/files/3402939762.pdf
    • http://elitsatodorova.com/uploadfiles/file/18485493506.pdf
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/16136677fe6bfc---58152461390.pdf
    • http://unitez.net/images/newtech/files/11973889612.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=cast+my+phone+to+computer
    • 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_off0000dce7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDCE7 16792 bytes
font_01_sfnt_off0000f4f9.bin
e52474b5a60821b8093059169fbb575b4a47fc41f0d3eeb12798e753c85af09a
pdf-font-stream PDF embedded font (sfnt) at offset 0xF4F9 17564 bytes
font_02_sfnt_off00012250.bin
63ef6653f5d133dc8648a5c7e5c0dd769800c73ce7fa04bba0547cab9220c312
pdf-font-stream PDF embedded font (sfnt) at offset 0x12250 10748 bytes