Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5c7108813c2ae22…

MALICIOUS

PDF

71.1 KB Created: 2021-09-17 18:26:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a902532a3edf1df60298f9dd166bf090 SHA-1: 24487df0bfce438ac2c4012804b62f8d74581422 SHA-256: a5c7108813c2ae22408211964d40aecae7694ebb751b94267c240a6f51b75727
164 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code or redirecting users. Several heuristics indicate the presence of link farms and compromised upload storage, suggesting an attempt to distribute malicious files or host phishing content. The ClamAV detection and ML classifier further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • 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.
  • 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://sireny.net/share/files/38394207640.pdf
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/0ffbf1b884659f66491126a050101698/redizufawedejukatawuwubel.pdf
    • http://azinsaghf.com/cache/fck_files/file/54524163103.pdf
    • http://asia-test.informacittadino.net/media/files/vitodelubejipav.pdf
    • http://hakanhurdacilik.com/userfiles/file/71727770903.pdf
    • http://koala-al.com/d/files/35063103896.pdf
    • http://hzaidele.com/images/upload/File/zitimidegulosegijopozemuk.pdf
    • https://e-midas.ro/files/file/loniduja.pdf
    • http://syarmarka.ru/userfiles/files/52319804050.pdf
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/0cb63877c9a10c36a35f9cd4d33487e9/salekeberesorotilaferov.pdf
    • http://newbiesites.com/userfiles/file/jexamenilodovinuxovan.pdf
    • http://hnspkjx.com/d/files/samig.pdf
    • https://abogadosaccidentealicante.centralcms.cloud/galeria/files/moruvekusonosabipid.pdf
    • http://bsa-billiard.by/images_from_html_editor/file/zipesadelu.pdf
    • https://coop-alternatives.fr/images/images/xujipotemel.pdf
    • https://forssh.com/userfiles/file/kowugukitemujimidusokuf.pdf
    • http://www.siposferenc.hu/html/47820909692.pdf
    • http://hongshengfish.com/uploadfiles/20210908/210908155109213921zo2sl1fxfhgb.pdf
    • https://apaman.ti-am.jp/js/ckfinder/userfiles/files/kevufone.pdf
    • http://donghotam.com/luutru/files/71082178447.pdf
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/161428e2131708---50694710169.pdf
    • http://www.me.ntou.edu.tw/ckfinder/userfiles/files/20210903_075920.pdf
    • http://xedaptheduc.net/app/webroot/uploads/files/35754946448.pdf
    • http://creativecoms.net/userfiles/file/wufavotib.pdf
    • http://styrexon.cz/userfiles/file/beniwazapu.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=rom+pokemon+crystal+gba
    • 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_off0000b5b4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB5B4 16792 bytes
font_01_sfnt_off0000cdc6.bin
de6167ba0ce630ca4501fbd5144442d405a2459b87373399738f3b25cf3d93d3
pdf-font-stream PDF embedded font (sfnt) at offset 0xCDC6 15516 bytes
font_02_sfnt_off0000f563.bin
13b48c80a4e0ff4c31652132cdc3bd76ab65d081ef1581402aa22de02835e6ad
pdf-font-stream PDF embedded font (sfnt) at offset 0xF563 11016 bytes