Malicious PDF — malware analysis report

Static analysis result for SHA-256 3559afe5813f6aa1…

MALICIOUS

PDF

77.3 KB Created: 2021-09-16 16:07:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 5d0fd0b056cdadb0b5a58567c85fa5ea SHA-1: f57651faebb68be3d0e105a9904de38c04a47049 SHA-256: 3559afe5813f6aa1e201c57520a2a4cd3d040f48736d7ea46a5733e6515422c8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links pointing to disposable hosting and compromised CMS upload storage, indicative of a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, specifically phishing or trojan distribution. The document body is unreadable, but the heuristics and URL analysis confirm the attack pattern.

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 http://nbnjl.com/userfiles/files/toxize.pdf In PDF document text
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/1613aadbde2e7c---kexajiradawizosu.pdfIn PDF document text
    • http://hotdeals24x7.com/ci/userfiles/files/31693235669.pdfIn PDF document text
    • http://bbbo.handyfriendship.com/upload/files/72354793939.pdfIn PDF document text
    • https://armenia4d.com/contents/files/16976826908.pdfIn PDF document text
    • https://bamfieldrental.com/userfiles/file/97452764409.pdfIn PDF document text
    • http://innospectrum.eu/hirlevel/file/didisivajopadisilofoxikim.pdfIn PDF document text
    • http://elturo.ru/img/upload/files/wobozobiwosexu.pdfIn PDF document text
    • http://wamer.org/userfiles/file/kevabonarojagelufifubowal.pdfIn PDF document text
    • https://citronixdeflection.com/nbloom/fckuploads/file/23926728185.pdfIn PDF document text
    • http://xn--80aer5aza.xn----htbdepbihnfb8cyg.xn--p1ai/ckfinder/userfiles/files/rotovabunulusazax.pdfIn PDF document text
    • http://baihsad.com/userfiles/files/20210905_055418.pdfIn PDF document text
    • http://fixafilm.se/userfiles/file/39574342716.pdfIn PDF document text
    • http://inspiredindianfoundation.org/uploads/33955153636.pdfIn PDF document text
    • https://testgit.begurholidays.com/uploads/userfiles/files/37734492823.pdfIn PDF document text
    • http://metrominicabs.com/survey/userfiles/files/sijugadifotunaxiwezonaw.pdfIn PDF document text
    • http://timocomputer.cz/files/file/36112947022.pdfIn PDF document text
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161398f1396df8---65619530149.pdfIn PDF document text
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/4e2e1ca91fe4399d16e72801f6638261/kaxafavetojepukeridoju.pdfIn PDF document text
    • http://boschvietnam.com/files/usersfiles/files/5883691539.pdfIn PDF document text
    • http://pension-erlkoenig.de/img/editor/file/77701654586.pdfIn PDF document text
    • https://swaarm.de/app/webroot/upload/files/rinusimatovokanexoga.pdfIn PDF document text
    • https://dobre-akce.cz/media/files/file/94890201185.pdfIn PDF document text
    • http://tantusmarina.com/UserFiles/file/383012201.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=kg+story+book+pdfPDF 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_off0000c8c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8C7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e0de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0DE 10476 bytes
SHA-256: 2f0b9e763751ae0cdabd1c0b337f3b143fa5cb998a1c217d48d0013618df5f10
font_02_sfnt_off0000f85f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF85F 18096 bytes
SHA-256: 500d196a0b849162af41da3c4c26b8992934dfeded318072a5d046d3de94808b