Malicious PDF — malware analysis report

Static analysis result for SHA-256 395c636ba1e36081…

MALICIOUS

PDF

91.5 KB Created: 2021-07-10 04:25:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ee4a6cc35344a7a5d0a65abcbae2a2ca SHA-1: 907a39b1467c85271c6ce300485de20e5a0101cf SHA-256: 395c636ba1e36081fc228bf4b57d244f46f3fe0fa092096a2f2bb70d622dc8eb
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised CMS upload directories and disposable hosting, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9932

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://huntic.ru/uplcv?utm_term=baby+give+me+one+more+chance+ashanti
    • http://www.rosabrockenhaus.ch/ckfinder/userfiles/files/57140190874.pdf
    • http://o2ashop.com/ckfinder/userfiles/files/19835312534.pdf
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1609820cb909d3---zipikimesurolalipejukule.pdf
    • https://space1500.com/wp-content/plugins/super-forms/uploads/php/files/26a5e9c307f30cbd9a4814036c3a510c/pumiboxisexejakuwoxo.pdf
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/160e63f7e8b93f---luwes.pdf
    • http://hasyo.net/files/file/nukar.pdf
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/865ded04d14cdade8603b7cc994de640/jiletefarika.pdf
    • https://www.uniqueartzz.com/wp-content/plugins/super-forms/uploads/php/files/5j7le56t3fbok42lo161bvf20d/31246634928.pdf
    • https://technok.cz/wp-content/plugins/super-forms/uploads/php/files/208cd98406997220f6690df66da59e0e/biwefaxadazebodawifuk.pdf
    • http://exmar.it/foto_fck/file/vasoxevebedavulamikuzavam.pdf
    • http://edilgroupdigiovanni.it/userfiles/files/pizofutelu.pdf
    • https://amrapalispot.com/userfiles/file/21630349739.pdf
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/1608ca04281b8e---wemozifejiti.pdf
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/371ecb94f49a1542fbca069e05e6767c/44187592189.pdf
    • https://vientangluc.com/upload/files/14852010550.pdf
    • https://sarujiovalente.com/wp-content/plugins/super-forms/uploads/php/files/7st9ot81poe9mn0glfrbefl6ug/ridovasefibevapef.pdf
    • https://tucsonhomewindowtint.com/wp-content/plugins/super-forms/uploads/php/files/4c941e820f8114789774226b9f4b86db/kurivurid.pdf
    • https://big-cash.de/wp-content/plugins/super-forms/uploads/php/files/49cqhnimdqi09na81m5o0d0q3d/40313629585.pdf
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/60c05c508d296c0f362232aacd0e3d55/12365391540.pdf
    • http://ypcalumni.com/clients/2/24/24042806289e0d450134266962f0a0d8/File/kubivowa.pdf
    • http://odpadykj.cz/UserFiles/File/40544718953.pdf
    • http://anhuicrew.com/upload_fck/file/2021-5-12/20210512190344595542.pdf
    • http://share-world.tw/userfiles/file/zitogidotuwitofukoso.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f6a0.bin
3b2665576e0e733557d54fd8b7ab9fbf951407a02dcda8f4f3f3dabcf3176750
pdf-font-stream PDF embedded font (sfnt) at offset 0xF6A0 1708 bytes
font_01_sfnt_off0000febe.bin
b45f3a84def7fbc51da8fb2ab8ca8e6f005f5bf9c634557e4e0c0c07dd976e44
pdf-font-stream PDF embedded font (sfnt) at offset 0xFEBE 11004 bytes
font_02_sfnt_off00011833.bin
bc55adf6c831cbbf3cef95b69de034d76987e06592607e2d1e92efe98255ebc5
pdf-font-stream PDF embedded font (sfnt) at offset 0x11833 18368 bytes
font_03_sfnt_off0001483f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1483F 16792 bytes