Malicious PDF — malware analysis report

Static analysis result for SHA-256 c91ce53a9f9c4d15…

MALICIOUS

PDF

83.9 KB Created: 2021-09-23 22:35:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2a8aadd122f7c685ab78bd2be39fba3a SHA-1: 8ee61cd0c22b6634b12fcf37b3829b3d8a296be4 SHA-256: c91ce53a9f9c4d15cc08ccb453165d408ae2fb0e2eabf795a32f1d0f0c436667
134 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is a malicious PDF detected by ClamAV as a phishing trojan. It contains embedded JavaScript, which is likely used to redirect the user to external URLs. These URLs are part of a link farm hosted on compromised or disposable domains, suggesting an attempt to distribute phishing content or further malware. The PDF's structure and embedded JavaScript indicate it's designed to exploit vulnerabilities or trick users into visiting malicious sites.

Machine Learning

  • Nyx PDF Classifier clean score 0.2133

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • External URI info PDF_URI
    PDF contains an external URL action
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://xn--bankkrtya-41a.hu/js/ckfinder/userfiles/files/11048229082.pdf
    • http://www.superior-inkjet.com/login/ckfinder/userfiles/files/91924410340.pdf
    • http://autoscuolemontagna.it/userfiles/files/9351408383.pdf
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/8f4cb1d6180623bb15506dc18de44680/nolasopalafukib.pdf
    • https://www.kindspring.org/inc/ckfinder/userfiles/files/polafubezulowegubam.pdf
    • https://demetraproject.eu/ckfinder/userfiles/files/kupirirubokuxaval.pdf
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612f088938a5b---16674532441.pdf
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612edf26586fc---besekukibuwojozozubidog.pdf
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/a78865035a74f34a4c55bdc02d389c9e/xaruliwipibaparapekigexa.pdf
    • http://zkqzl.com/uploadfile/file///2021091101111587.pdf
    • http://www.stadion-zarya.ru/ckfinder/userfiles/files/bekizamefas.pdf
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613808f44f986---sijaborudoj.pdf
    • http://mauchlineware.com/html/chapelstreet/web/userfiles/files/fedamiritof.pdf
    • https://www.dogandemir.av.tr/paketler/ckfinder/dosyalar/files/wuwufaluzasaratutiki.pdf
    • http://papinchess.ru/userfiles/file/fusotugaz.pdf
    • http://wordtmann.beckbauer.eu/ckfinder/userfiles/files/dodosodaziganeta.pdf
    • https://classconnbio.com/img-jacson/files/76877857243.pdf
    • https://108pizza.pl/uploads/userfiles/files/sebizenapobepusejigidokiz.pdf
    • https://ipkameros.lt/userfiles/file/50259746728.pdf
    • http://aedelsur.com/contenido/files/78875616455.pdf
    • https://southernwashpros.com/nbloom/fckuploads/file/25373131837.pdf
    • http://hz-kontejnery.cz/ckfinder/userfiles/files/kudavugokug.pdf
    • http://koreaseowon.com/ckupload/files/jixumapokefabegumawevomok.pdf
    • http://www.vljainandco.com/userfiles/files/tijewifeser.pdf
    • http://turismo-usa.com/files/others/44839981377.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=talking+tom+2+cheats
    • 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_off0000f05c.bin
2a3e18703fad304941f12138fd5f17086248b52428df2086f99cacea4ce2c4f8
pdf-font-stream PDF embedded font (sfnt) at offset 0xF05C 17488 bytes
font_01_sfnt_off00011ddb.bin
e8cc8fcbfd77182be4c1a512f28330a535ef5c5c8c6640b21ed136fb082b8505
pdf-font-stream PDF embedded font (sfnt) at offset 0x11DDB 10752 bytes
font_02_sfnt_off0001367b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1367B 16792 bytes