Malicious PDF — malware analysis report

Static analysis result for SHA-256 f91b0286371d98bb…

MALICIOUS

PDF

78.2 KB Created: 2021-09-19 07:05:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 7696daf0980071b7304fa0066bd134cb SHA-1: fb72a95c0a7795ee46a959ece435b47eb7410d14 SHA-256: f91b0286371d98bb0e33b6ade3158dc000ab4a9614d5b64ca7d5e7c5e58ff0fb
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to disposable hosting or compromised WordPress sites, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://wastran.ru/uplcv?utm_term=led+blinker+pro+apk PDF link annotation
    • http://dija.lv/public/userfiles/file/5126331399.pdfIn PDF document text
    • http://school19-zav.ru/userfiles/file/forebilowakajoxus.pdfIn PDF document text
    • http://hiroshima-teishaku.com/userfiles/file/92289573121.pdfIn PDF document text
    • http://ersatzmonitor.de/userfiles/file/48926700006.pdfIn PDF document text
    • https://novamakine.com/upload/ckfinder/files/vegolujag.pdfIn PDF document text
    • http://metamorfoza-krosno.pl/userfiles/file/96047346917.pdfIn PDF document text
    • https://rasathantrananotech.com/ckfinder/userfiles/files/21253785501.pdfIn PDF document text
    • http://b-solutions.net/userfiles/file/falubezipefojajemubure.pdfIn PDF document text
    • http://chinalabware.ru/d/files/47886261685.pdfIn PDF document text
    • http://willettelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/83020855453.pdfIn PDF document text
    • https://crownprolaw.cn/userfiles/Proj_Name/files/lenew.pdfIn PDF document text
    • https://nezrenpin.com/calisma2/files/uploads/29801284129.pdfIn PDF document text
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16135f4da1f4b1---fatosexuzosodupozif.pdfIn PDF document text
    • http://bebelino.ru/userfiles/file/fegezulanopeli.pdfIn PDF document text
    • http://studiotecnicodambra.eu/userfiles/files/pemolex.pdfIn PDF document text
    • https://rimi.sk/userfiles/file/pukezo.pdfIn PDF document text
    • http://duonglaohanoi.com/userfiles/file/2280611861.pdfIn PDF document text
    • http://deborahkay.com/ckfinder/userfiles/files/beponitenokugekisawanup.pdfIn PDF document text
    • https://optical-axis.com/uploads/files/202108312301298916.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/161332831a29b8---80006412402.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135ba9906ad3---62746975746.pdfIn PDF document text
    • https://kiofruits.com/admin/uploads/files/3440338362.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cd72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD72 10308 bytes
SHA-256: 04185c241f88bb3dedb3554aed6012ba20121cc7321e866c4db223327f2f1038
font_01_sfnt_off0000e46a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE46A 18024 bytes
SHA-256: 3615b1857b7fc91d61b4f4b00e84e8d3790b824f16fc62409ef80ddc9ed5f295
font_02_sfnt_off00011356.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11356 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1