Malicious PDF — malware analysis report

Static analysis result for SHA-256 9920307b2aa0dbab…

MALICIOUS

PDF

88.1 KB Created: 2021-09-13 12:48:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: dc6dca933da25c1e3b8c5e2a051c6e2d SHA-1: 95012cd304296ff36d5b1b261c2356b25a18da76 SHA-256: 9920307b2aa0dbab35768aad85b3cc7f4b8a65a373538bfc33c73838ceb862c5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, suggesting a phishing or malware distribution scheme. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this, indicating the PDF is part of a link farm designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://coretry.ru/uplcv?utm_term=android+sms+pdus PDF link annotation
    • http://alpha-cp.com/userfiles/file/rixisetelufanofuwitirorur.pdfIn PDF document text
    • http://polymer-optix.de/userfiles/file/73086187174.pdfIn PDF document text
    • http://virtualcharityevents.com/vce_cake/files/files/pawexasuvixexosareriziku.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/ccd7m8spo13ksnqaunfkthj0ei/zesatuvurupexamarot.pdfIn PDF document text
    • https://vallejardin.com/wp-content/plugins/super-forms/uploads/php/files/bd33d8e9cfde3b33cb63ebb1b4067191/romeredi.pdfIn PDF document text
    • http://fxmeat.com/upload/file/2f0d189eaa741827b4011104937d0fab.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/161361019c4f2c---mirib.pdfIn PDF document text
    • http://skupka54.ru/upload/m/14985319808.pdfIn PDF document text
    • http://855solution.com/htdocs/cljr/data/files/96673257776.pdfIn PDF document text
    • http://alacarte-husum.de/userfiles/file/jaronuzotadabovujekewedi.pdfIn PDF document text
    • https://hrmconsulting.biz/upload/files/musibexenugubasexig.pdfIn PDF document text
    • http://eamenfaraz.com/cache/fck_files/file/dimobowotilulazetexavila.pdfIn PDF document text
    • https://www.mds-horizons.com/upload/files/wowebifijolikun.pdfIn PDF document text
    • http://falegnameriacastiglione.it/userfiles/files/tipabutukakelujuronomuj.pdfIn PDF document text
    • https://santa.sg/images/users/00000000/files/27845125879.pdfIn PDF document text
    • http://shangrilayunnan.com/ckfinder/userfiles/files/mokuki.pdfIn PDF document text
    • https://hzautomatisering.nl/userfiles/file/31785787767.pdfIn PDF document text
    • https://navliecky.net/userfiles/file/41948847891.pdfIn PDF document text
    • http://www.hermosabeachbungalows.com/userfiles/files/jikijerosif.pdfIn PDF document text
    • https://bonaparte.cappencms.com/templates/files/77203526604.pdfIn PDF document text
    • http://pastoret.it/userfiles/files/tusemudef.pdfIn PDF document text
    • http://xinchenfast.com/upload/file/tuvumipowawozarikuvas.pdfIn PDF document text
    • http://velomagazin.hu/UserFiles/file/guravenosizur.pdfIn PDF document text
    • https://mimpiindah2.com/contents/files/tugesurukimafaxutu.pdfIn PDF document text
    • http://agecarekorea.com/ckupload/files/55432803524.pdfIn PDF document text
    • http://cuanhuaabshanquoc.vn/files/resagitopuguzibarobate.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_off0000f3f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F4 10196 bytes
SHA-256: 57bdd4c42dc8f09f274349de9607200ac2cb5bd131cc6a0934c138d700c17873
font_01_sfnt_off00010ab7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AB7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000122c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122C9 18116 bytes
SHA-256: a127f081dd2d2289e96533dee86ac1f406686e2a1d2dccdfa471daf055f7fed0