Malicious PDF — malware analysis report

Static analysis result for SHA-256 a15de5cc05cb0b7e…

MALICIOUS

PDF

79.3 KB Created: 2021-09-18 20:25:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 3fd4c65caa8a81d8207b68bf22cf91ab SHA-1: 043ab39e53e79e27139f35271b7d1e7953db55d2 SHA-256: a15de5cc05cb0b7e1e740adf90be5da56e2c6e56c223fcdae1d63565a5529fac
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, with one heuristic specifically identifying it as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript is likely used to obfuscate the malicious links or redirect the user.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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
  • 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
  • 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://ychnjl.net/userfiles/files/74690334471.pdf In PDF document text
    • http://palirna-frydek.cz/uploaded/file/99767788118.pdfIn PDF document text
    • http://hoaiduc.edu.vn/ckfinder/userfiles/files/wibawozak.pdfIn PDF document text
    • https://www.orthovision-lublin.pl/ckfinder/userfiles/files/18210460846.pdfIn PDF document text
    • http://www.gpe-el.pro/ckfinder/userfiles/files/11197854750.pdfIn PDF document text
    • http://fujavietnam.com/images/Download/perake.pdfIn PDF document text
    • http://geerhannutpourreussir.be/docs/upload/files/95578867255.pdfIn PDF document text
    • http://landpas.pl/upload/file/jokibolutimobopi.pdfIn PDF document text
    • http://2013.letnifestiwal.pl/ckfinder/userfiles/files/lezavigiwikimu.pdfIn PDF document text
    • https://www.abrasco.org.br/ckfinder/userfiles/files/99808255806.pdfIn PDF document text
    • http://cuoredicane.it/userfiles/files/97777923931.pdfIn PDF document text
    • http://xn--80age2amlc.xn--80adxhks/pics/images/file/65811914993.pdfIn PDF document text
    • http://opuspointpartners.com/ckfinder/userfiles/files/satexadejajexuresukowig.pdfIn PDF document text
    • http://rama-sp.com/rama/webroot/js/ckfinder/userfiles/files/96979846681.pdfIn PDF document text
    • http://billsky.ee/files/file/kejurugefa.pdfIn PDF document text
    • http://agriturismoilnoceto.com/userfiles/files/foziriwa.pdfIn PDF document text
    • http://illinoislivestock.org/userfiles/file/kekitovegu.pdfIn PDF document text
    • http://xn--80aafmoni2biho.xn--p1ai/admin/ckfinder/userfiles/files/xusanikaxaxokefoji.pdfIn PDF document text
    • http://camberwelltaxi.com/survey/userfiles/files/xagukafo.pdfIn PDF document text
    • http://maquinandoysubastando.com/dleyes/admin/fotos/file/16402563424.pdfIn PDF document text
    • http://newo.ru/files/files/79684151380.pdfIn PDF document text
    • https://vwb.mrv-educationservices.com/content_file/files/88550590280.pdfIn PDF document text
    • http://www.parinet.fi/tiedostot/files/33826402081.pdfIn PDF document text
    • http://asid.rw/userfiles/file/49844949082.pdfIn PDF document text
    • https://allegypttours.net/userfiles/files/zuralojoke.pdfIn PDF document text
    • http://kaizousha.com/js/upload/files/71431090737.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=2048+3d+plus+mod+apkPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cf4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF4C 18248 bytes
SHA-256: d641357f61b42d238682958974de3495748bec534f916edbbcb61faf1700297a
font_01_sfnt_off0000feba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEBA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000116d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116D1 10824 bytes
SHA-256: 4bb169f9e57d73c7a90b56d884dd8e06acfbc86725c815c0a1a18cf2fde28414