Malicious PDF — malware analysis report

Static analysis result for SHA-256 6ff81ccfb033ec72…

MALICIOUS

PDF

86.4 KB Created: 2021-09-15 23:31:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 8b5d6a1dec5e903a606066b6918d5a1b SHA-1: 6e12b65e0916ae4328cd62a86639cb7749b76bd3 SHA-256: 6ff81ccfb033ec72cd3fdfe2f3a80575fd7491c07e0e39af4481c0ee7904d0d5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ML classifiers and ClamAV. It contains numerous links pointing to compromised websites and disposable hosting, suggesting a phishing or malware distribution scheme. The presence of external URI heuristics and link farm indicators further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9930

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://medvor.ru/uplcv?utm_term=lulubox+free+fire+diamond PDF link annotation
    • http://61kidsclub.com/userfiles/file/45997498858.pdfIn PDF document text
    • http://westernmaki.com/uploads/files/kunawutovo.pdfIn PDF document text
    • http://medicaldistri.com/ckfinder_files/files/wopaxev.pdfIn PDF document text
    • http://first-group.kr/ckupload/files/zobiwamivenexedinojewodi.pdfIn PDF document text
    • https://jaurrieta.net/USERFILES_JAURRIETA/files/12262391292.pdfIn PDF document text
    • https://hongmao.tw/uploads/files/202109051131314309.pdfIn PDF document text
    • http://uhy-th.com/image/upload/files/zodoligaditufojig.pdfIn PDF document text
    • http://hanasushi6.com/uploads/files/mixebeturowu.pdfIn PDF document text
    • http://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/1613be6f813dc8---78773027554.pdfIn PDF document text
    • http://peaceinsrilanka.lk/userfiles/file/rafukejivabavi.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141622788401---68051608687.pdfIn PDF document text
    • http://ulsantour.com/FileData/ckfinder/files/20210909_2DD50E6DC67823D4.pdfIn PDF document text
    • http://pekbdt.com/filespath/files/20210903033008.pdfIn PDF document text
    • http://www.kroonzuivel.nl/ckfinder/userfiles/files/15018148230.pdfIn PDF document text
    • http://vimbark.sk/editor_uploads/files/tuwupom.pdfIn PDF document text
    • https://www.borzabadi.com/ckfinder/userfiles/files/99209717336.pdfIn PDF document text
    • http://codemessaging.net/ckfinder/userfiles/files/39181629988.pdfIn PDF document text
    • https://niboparis.com/upload/fckeditor/file/1631468782_1.pdfIn PDF document text
    • http://foxadv.net/file/175904415.pdfIn PDF document text
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/161340cd183017---roladam.pdfIn PDF document text
    • http://vedepcuaem.com/luutru/files/98300899625.pdfIn PDF document text
    • https://allmassage.net/upload/file/20210909110500.pdfIn PDF document text
    • http://stoewebdesign.no/userfiles/file/13291754362.pdfIn PDF document text
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cc7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC7D 10548 bytes
SHA-256: 1358b00b0a61006da28f86a16cf7015d4cb0a9dbef11a8c78e75660ff3394741
font_01_sfnt_off0000e46b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE46B 16232 bytes
SHA-256: e06ebeaa2bb94d9bf14337b0794fec2c9c4a66e30291689b6f6234bfe360c8a5
font_02_sfnt_off0000fa4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA4A 22532 bytes
SHA-256: 17673130b8c31f90b81423a5903d72bec4dee1b8437655fc3737f69a7975b24c
font_03_sfnt_off000133b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x133B1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1