Malicious PDF — malware analysis report

Static analysis result for SHA-256 a43cd20433632728…

MALICIOUS

PDF

80.0 KB Created: 2021-09-08 19:20:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 81d5899ed6815748a2161633d8811a87 SHA-1: 9dfa4b3eda41aecb21b6224f33a581288a1e3118 SHA-256: a43cd20433632728093d4f99acf049431cc2bd36ca3dab58b0288a24b0105899
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating it likely exploits a vulnerability or contains malicious content. Heuristics reveal it functions as a link farm, directing users to various domains, some hosted on compromised CMS platforms, suggesting an attempt to distribute further payloads or conduct phishing. The presence of multiple external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://tindangnhadat.vn/upload/files/97921394600.pdf
    • https://inprovitcaribe.com/ckfinder/userfiles/files/87064504370.pdf
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/52679616f5beb35c95d7377b5d9931b4/zozexezudemunivomix.pdf
    • https://clicksnepal.grnca.org/img/files/files/piwabujiposesex.pdf
    • https://phatgiaolongan.com/upload/ckupload/files/75995591244.pdf
    • http://farashimirooz.com/files/wevobasokerew.pdf
    • http://energo-market.ru/sadm_files/32495962796.pdf
    • http://jtylek.pl/Upload/file/60499692627.pdf
    • http://herfon-machinery.com/images/ckfinder/files/20210901054550.pdf
    • http://geometrarontani.it/userfiles/files/42874699291.pdf
    • http://sendedianqi.com/upload_fck/file/2021-9-4/20210904004722449430.pdf
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16133c6cb52016---43690078319.pdf
    • http://geasit.it/userfiles/files/34302852948.pdf
    • https://j26clean.com/upload/files/xarugedu.pdf
    • https://digitaldaya.com/imagenes/file/ditoxobuzido.pdf
    • http://zsdbiopharm.com/upload/files/90887066402.pdf
    • http://secohthailand.com/file_media/file_image/file/38592539020.pdf
    • http://bidmitt.com/img/files/file/43491488297.pdf
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161365ffab1f89---selubiwutugexe.pdf
    • http://munnarinfo.in/userfiles/file/93622956368.pdf
    • http://vkp.ru/upload/global/file/69989102896.pdf
    • http://www.papelerialapiceros.es/ckfinder/userfiles/files/togeziwu.pdf
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/16133f1e1b7bfb---89738770496.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=accurate+clock+pendulums+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_off0000d67a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD67A 16792 bytes
font_01_sfnt_off0000ee8c.bin
c1d8da9e48fc866934b0f5ea0df8c0101789082762681a9262c9999f52224df8
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE8C 16652 bytes
font_02_sfnt_off0001194b.bin
f097ff6eca6fbe458080f93727251e0bd3c0d156e923321e8081e7e3e9f610e3
pdf-font-stream PDF embedded font (sfnt) at offset 0x1194B 10864 bytes