Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b1f906453bee67f…

MALICIOUS

PDF

84.0 KB Created: 2021-09-20 03:25:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4e9df21b9008f455fcce773825308978 SHA-1: 084b7caf09b988c205d6a397a43ae50840d00729 SHA-256: 3b1f906453bee67fef5e09f45fdb92d0d9158444f8ddb75d099948fc2d1aeebf
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 CMS upload directories, indicating a link farm or SEO spamming operation. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports the interpretation of this file as a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://wawa757.com/uploads/files/32343192109.pdf
    • http://vektor-bezpeki.com/userfiles/files/29571552717.pdf
    • http://dorp.pl/userfiles/files/gonowibutoxomadit.pdf
    • https://ylwlgwadmin.ylwl.cn/upload/files/9112483263.pdf
    • http://mtcongnghiepxanh.com/upload/fckimagesfile/26105576693.pdf
    • http://eternoohydro.com/d/files/49957893485.pdf
    • https://ksboutlet.com/file/files/31100599817.pdf
    • http://uleshuzatshop.hu/files/file/fikejosugabenobatapu.pdf
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/161310b47dd564---gomazukowawamu.pdf
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/uupgnphe0f86agmv3on6ob37h556lucu/pagafazulaxotajazolo.pdf
    • https://atvatextile.com/upload/ckfinder/files/piwesibojor.pdf
    • http://palyavalaszto.hu/teszt/upload/file/30188602708.pdf
    • http://www.galiantsolutions.com/emailimages/file/75878382202.pdf
    • https://karaari.leaddeehub.com/userfiles/files/32084208726.pdf
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/161457ff3eb59a---66209450187.pdf
    • http://sh-songshi.com/admin/upimg/file///80585997115.pdf
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/161463be401ba4---9765158516.pdf
    • http://ahzycw.com/upload_fck/file/2021-9-13/20210913021327144697.pdf
    • http://hoteldanang.vn/uploads/images/files/lazokerezamola.pdf
    • http://abwvictory.com/uploads/files/95987753123.pdf
    • http://sjar-tech.com/uploadfile/file///2021091901022663.pdf
    • https://skykharchono.mn/editor/files/3432262419.pdf
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f2e7714d9b---78199264660.pdf
    • http://corse.annuaire-regional.com/ckfinder/userfiles/files/82444256159.pdf
    • http://www.kickcommerce.com/userfiles/file/gupawi.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=unturned+motorcycle+id
    • 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_off0000de1f.bin
f08e97ae08e7c57cea9f8c51846ddcc07656548daf9402e5216c87d3787fd428
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE1F 10420 bytes
font_01_sfnt_off0000f5aa.bin
2b1de99912b50da8b65828448992bdec936bbb322f15bf74bdb5909d90e6f606
pdf-font-stream PDF embedded font (sfnt) at offset 0xF5AA 20104 bytes
font_02_sfnt_off00012a4d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12A4D 16792 bytes