Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f7a573c4f0f9815…

MALICIOUS

PDF

72.1 KB Created: 2021-09-25 16:29:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5b4e347e5b8f65fa19d10099c47681c0 SHA-1: b949ecde381aea80aa9a58dc63bc732d32ca5151 SHA-256: 4f7a573c4f0f9815966e022a4b4ca720759f519cdcc5e4afc8e46e779bc7cc02
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. The document body was unreadable, but the heuristic firings and URL analysis are sufficient to infer the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://serpavenger.com/ckfinder/userfiles/files/sosinif.pdf
    • http://robedecreateur.com/img/files/xumiz.pdf
    • https://mimpishio1bet.net/contents/files/39364402643.pdf
    • http://urjabatteries.in/userfiles/file/80594114039.pdf
    • http://filipdegreef.be/uploads/files/wafatojexiloxupesum.pdf
    • https://www.peltonfell.org.uk/ckfinder/userfiles/files/mewujitaxufilexe.pdf
    • http://jadeite.ru/images/file/noniligosupusejawupa.pdf
    • https://www.area-tlc.com/public/ckfinder/userfiles/files/bizadarudumevurus.pdf
    • https://myagenda.myagenda.cz/pictures/editor/files/sizivelodaduwede.pdf
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/5p4b9d7lkttk6io3p0g7dvu48s/43312700031.pdf
    • http://cupta.org/userfiles/files/20210907101630.pdf
    • https://giridhareye.org/ckfinder/userfiles/files/nopimir.pdf
    • https://beldapin.com/calisma2/files/uploads/85939666758.pdf
    • https://mastirz.com/userfiles/files/besanudam.pdf
    • http://gysanya.com/upload/file/210917082150883087gb8dfyfvzvfo.pdf
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/1612feb93b8a50---mabebituvesebusejes.pdf
    • https://onecre.com/images/content/files/nuwesubosatozigujozamakiw.pdf
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/1613e0b0db83a3---17652988599.pdf
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/16138940343d17---8956944177.pdf
    • http://daithanhnam.com/upload/files/15663427140.pdf
    • https://idroilektriki.gr/files/file/32914366536.pdf
    • https://defi128.com/userfiles/files/fiwidelowolakuvo.pdf
    • http://mayepnuocmia.vn/data/ckfinder/files/29028797930.pdf
    • http://csc0311.com/userfiles/file/20210912194353_5tzz6s.pdf
    • http://oletrans.sk/editor_uploads/files/65009689987.pdf
    • http://qlionshousing.ca/userfiles/file/zegut.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=mxq+pro+4k+update
    • 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_off0000b778.bin
09fa561783e1d500b8603a2659ea2759a1cb30dc439f0c78ebecb2006b2ee267
pdf-font-stream PDF embedded font (sfnt) at offset 0xB778 17292 bytes
font_01_sfnt_off0000e37f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE37F 16792 bytes
font_02_sfnt_off0000fb96.bin
93c77f2c5693148d12cf4106e624887ae371487f7a75841ff21008a4e4e1104a
pdf-font-stream PDF embedded font (sfnt) at offset 0xFB96 10484 bytes