Malicious PDF — malware analysis report

Static analysis result for SHA-256 34ded99a5edb4915…

MALICIOUS

PDF

81.2 KB Created: 2021-09-16 20:48:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b05814c678b5fd81a5986d851f4ebbab SHA-1: fb15510ce5336e3ba54854e845c9d7b9fa7d62f6 SHA-256: 34ded99a5edb4915592336230dfa1cb33549f174830f9dabc00f0aab5c95d16f
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, and exhibits characteristics of a PDF link farm. Multiple heuristics indicate the PDF contains numerous external URIs and links to compromised CMS uploads and disposable hosting, suggesting an attempt to lure users to malicious content. The document body is heavily obfuscated, preventing analysis of its direct content, but the overall structure points to a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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 https://pistant.ru/uplcv?utm_term=viewpoint+2+grammar+extra+answer+key
    • http://actybrain-consult.com/Upload/files/wojovedavopoki.pdf
    • http://www.lavalledesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/161301c7f068a5---wowivujubejunulinoxi.pdf
    • http://hockeydh.com/files/ups/files/sutifipusew.pdf
    • http://antitumor.org/filespath/files/20210912125640.pdf
    • https://globalcircle.club/userfiles/file/25132498205.pdf
    • https://il-gusto.com/images/file/71546976276.pdf
    • https://gameclub.by/uploads/files/fetego.pdf
    • http://kpotplace.com/uploads/files/29797637527.pdf
    • http://iamsong.vn/uploads/files/dejoridavonavuzopev.pdf
    • http://agppi99.pretty-match.com/upload/files/lorefodunekuran.pdf
    • https://generalaudit.pl/eurostyl/photos/file/1961390608.pdf
    • http://carsonpokebar.com/uploads/files/12432722009.pdf
    • https://happyjourney.webtrails.in/ckfinder/userfiles/files/56898131714.pdf
    • https://dolnoslaskialarmsmogowy.pl/imgturysta/files/16474898178.pdf
    • http://transcash.com/ci/userfiles/files/57852568466.pdf
    • http://konditsionery-odincovo.ru/upload_picture/file/4515084654.pdf
    • http://se-ty.ru/uploads/userfiles/file/potopuvibe.pdf
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/16135ce037d8b9---27653705275.pdf
    • http://rujiahk.com/uploadfiles/file/fafoxavuwuriwuf.pdf
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161371c2dc8935---10992850342.pdf
    • https://zhavezbozi.cz/data/file/buniwisik.pdf
    • https://villanakarin.com/userfiles/files/59374041672.pdf
    • https://inprovitvenezuela.com/ckfinder/userfiles/files/2392072484.pdf
    • http://alajwakh.com/uploaded_files/userfiles/files/ximajenerutado.pdf
    • http://yer-krasnodar.ru/ckfinder/userfiles/files/rabatumivuwesatukofaxisa.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_off0000d399.bin
1b35751ea4c95c4c234556327862735a72943ef0add09dd891fea745f95823b3
pdf-font-stream PDF embedded font (sfnt) at offset 0xD399 18904 bytes
font_01_sfnt_off0001051c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1051C 16792 bytes
font_02_sfnt_off00011d33.bin
1c0f1351f882af7c1e9471cc7d840a1f6f7c0e45f21ffc22581aea283037ffb9
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D33 11032 bytes