Malicious PDF — malware analysis report

Static analysis result for SHA-256 d827ef8d9d34689b…

MALICIOUS

PDF

78.1 KB Created: 2021-09-07 07:26:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 9d4f84b67d5bc59b74eb51475b8237a7 SHA-1: 80168b68c1dfee6db1f02228b7736dc6effbc2ff SHA-256: d827ef8d9d34689b9135f347b73d16e1c6745d36c48ea6603f4494cf304a8ce5
164 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, flagging it as a phishing trojan. It functions as a link farm, containing numerous URLs that point to compromised websites and potentially malicious PDF files. The presence of a 'download button' heuristic further suggests a lure to trick users into downloading further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/6314a2683011d73402bdd08065088dd9/99587201877.pdf In PDF document text
    • http://oldtimerclub-thueringerberg.at/images/file/wesejojikuvumovopuzorub.pdfIn PDF document text
    • http://mamam.by/upload/File/file/jasusopozipat.pdfIn PDF document text
    • http://aksaaydinlatma.com/img/editor/image/file/9157963741.pdfIn PDF document text
    • https://cvsc.co/userfiles/file/gememigamekixiru.pdfIn PDF document text
    • http://mijinmotor.com/fckeditor/userfiles/file/2020476027.pdfIn PDF document text
    • https://rotterdampools.com/contents//files/25671164160.pdfIn PDF document text
    • http://nextgt.eu/uploads/file/wiruz.pdfIn PDF document text
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/1243656e85ad73bed4de321d06a4b228/muminijisojuwukadumuta.pdfIn PDF document text
    • https://fablab808.com/nbloom/fckuploads/file/87548604468.pdfIn PDF document text
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ee6035d62e---59185628198.pdfIn PDF document text
    • http://yevres.fr/ckfinder/userfiles/files/99047205383.pdfIn PDF document text
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bc330dc429---4646547637.pdfIn PDF document text
    • https://cncostruzioni.com/userfiles/file/kupivuruxapexeka.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfd20830820---50437121291.pdfIn PDF document text
    • http://vervesimuhub.com/userfiles/file/11236248717.pdfIn PDF document text
    • https://laurallo.com/ckfinder/userfiles/files/mejuvoko.pdfIn PDF document text
    • https://xn--80aaa1anac6cg.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/7b8183727f4b26246c7255f6070c6b04/66732407198.pdfIn PDF document text
    • http://adaviestransportltd.com/userfiles/file/55905599502.pdfIn PDF document text
    • http://kythuatviet.vn/uploads/userfiles/file/17097791357.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/5d2jdqeig677i72ohmraa7os44/84716447295.pdfIn PDF document text
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc3a3717e43---basavezalibat.pdfIn PDF document text
    • http://creptiles.dk/userfiles/file/99582660345.pdfIn PDF document text
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/7534e8a51ab0d5394c9f88b68026b4ac/befuxarijipup.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=xml+document+to+pdf+converter+onlinePDF 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_off0000cda9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDA9 17044 bytes
SHA-256: ff3eccc1ba502b7f1e24fca490e0615106c68bd21d3aeb187dc3ec24eebc288e
font_01_sfnt_off0000fa14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA14 10624 bytes
SHA-256: 92835c94a38c2e7d1122ef161181046911f7eb95de80a3fab2477c98f7127f69
font_02_sfnt_off00011244.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11244 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1