Malicious PDF — malware analysis report

Static analysis result for SHA-256 6af5de58bdddfd10…

MALICIOUS

PDF

77.5 KB Created: 2021-09-19 04:55:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 19930efc9846bc5258c7f870677937fa SHA-1: 2490f14c4d8c1435d9ea8b99adf4a5b5154ab03c SHA-256: 6af5de58bdddfd10e4745022824ab40a602f8829ee223f892fce689f27272174
156 Risk Score

Malware Insights

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

The PDF contains a significant number of external URIs and link farms hosted on various domains, many of which appear to be compromised or disposable. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. The document body is heavily obfuscated and unreadable, providing no direct content clues, but the heuristic firings and numerous URLs point to a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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
  • 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://smidgel.ru/uplcv?utm_term=change+textview+style+programmatically+android
    • http://tonyprins.nl/images/uploads/file/10381349732.pdf
    • http://nprofit.hk/userfiles/57877261684.pdf
    • http://ttccid.com/userfiles/files/20486158561.pdf
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/161348b8a7176e---42482109635.pdf
    • http://internet-trade.cz/UserFiles/file/zitinitirogor.pdf
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161359ec8a1d26---84893171865.pdf
    • https://opsclown.it/ckfinder/userfiles/files/86960477660.pdf
    • https://yocarbroker.com/upload/ckfinder/files/33582471898.pdf
    • https://istanbulbalbir.com/upload/ckfinder/files/tewugazufasadu.pdf
    • http://fongyoskert.hu/userfiles/files/wufukagudezujurasinepe.pdf
    • http://uniradioweb.info/userfiles/files/70249311540.pdf
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613c83cfae047---47760381744.pdf
    • https://audreyheselmans.com/_files/file/zigowadejinowojovugetiri.pdf
    • https://vico-domrep.com/ckfinder/userfiles/files/fagune.pdf
    • http://dytac.hk/userfiles/47103376242.pdf
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/96ku1d7isujgqv0150h8k3qcis/nofovedoba.pdf
    • http://lifeline-sports.com/files/file/42606274904.pdf
    • http://urbanconstructions.org/images/uploadedimages/file/93137616066.pdf
    • http://slsnn.ru/content/files/66597141279.pdf
    • http://qbcar.ru/ckfinder/userfiles/files/99743656066.pdf
    • http://jinruily.com/UploadFile/file/20210918103208883.pdf
    • http://lidaoxc.com/upload/files/jubugevupedinajupij.pdf
    • http://impex-italia.it/userfiles/files/74590860523.pdf
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146680730024---92500984486.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_off0000c4e2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC4E2 16792 bytes
font_01_sfnt_off0000dcf9.bin
699ee152527c547a47809d9117f89df5ae64ccdfc4ee3ecc63583a6ee4317998
pdf-font-stream PDF embedded font (sfnt) at offset 0xDCF9 11360 bytes
font_02_sfnt_off0000f76f.bin
852be778de792074402f83c4800fc7cd2932a5dc3caf881e0d2f42ba98577d90
pdf-font-stream PDF embedded font (sfnt) at offset 0xF76F 18792 bytes