Malicious PDF — malware analysis report

Static analysis result for SHA-256 0a70b8eca5b86c55…

MALICIOUS

PDF

89.9 KB Created: 2021-08-02 14:06:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 20e1a7d4f6a3cda68090b6d01c1a4122 SHA-1: 14abd1af3bcbb10af238c70ed3f58d03134b8135 SHA-256: 0a70b8eca5b86c5514a12e8a76d321a55c817859ecbfb6cb2581fcf98c814cd9
156 Risk Score

Malware Insights

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

The PDF contains a link farm directing to numerous other PDF files hosted on various domains, many of which appear to be compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, providing no direct user-facing content, but the heuristic firings clearly point to a malicious link distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://portamarioarchitetto.eu/userfiles/files/zejogazapidorumamawux.pdf
    • http://szpital-sulecin.pl/images/fckfiles/file/kulolovexak.pdf
    • http://www.ibadirect.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a08f9234fc---majikalukopikifodumuf.pdf
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/ab8c0953b9f349cb91c04c12b2295c32/rutufiguwadop.pdf
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16090f677bea6c---69681283705.pdf
    • http://goldnumber.info/userfiles/file/zujakuniwefalub.pdf
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d1f0d88de17---sivixekakorokowunetejaw.pdf
    • http://xn----gtbercbfedtm3b.xn--p1ai/admin/ckfinder/userfiles/files/fajazutinukalewoxano.pdf
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/053fb8756c2f33c64f71d38cc4f55509/savufejinimivoremitasuwid.pdf
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/b30c0fbf15eac2ad7ca5e54ba78e1a4a/jiwalijaxugivevosig.pdf
    • http://timnhanhonline.vn/upload/files/92804582413.pdf
    • http://assushop.com/userfiles/assushop.com/file/60092858150.pdf
    • http://think6.net/ckfinder/userfiles/files/20210717105403.pdf
    • http://sjar-tech.com/uploadfile/file///2021061516104171.pdf
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/488213131b9e867299e1c70b130da5aa/fezifu.pdf
    • http://evpltravel.com/xv_image/file/waruxuzote.pdf
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/16102a258ef96f---sipire.pdf
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b9f032a9eaa---35863281976.pdf
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160edfce62f3cb---turidudapoxenanagimod.pdf
    • https://hr-serdahel.hu/images/file/fomuralevururemenamowaj.pdf
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/160c5e44e6ee98---65639276888.pdf
    • http://antik-cafe-bergen.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ad37376bfe2---18063441828.pdf
    • http://www.retorika-zidar.si/ckfinder/ckeditor_uploaded_files/files/xikeravorozuna.pdf
    • https://vetranhtuongmamnon.vn/wp-content/plugins/super-forms/uploads/php/files/j19ndbko0kf047g2al1m2fnhk0/74221977853.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=standoff+2+mod+menu+apk+download+2020
    • 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_off0000f81d.bin
5593a53035f0c576b8d19750145db9d9eef3f06fc7647d85c6b03240dae6ef70
pdf-font-stream PDF embedded font (sfnt) at offset 0xF81D 17552 bytes
font_01_sfnt_off00012608.bin
44e292f31e83a36e939f9c8d81a80170e7126725e654ef586bdb1b9fd507ba76
pdf-font-stream PDF embedded font (sfnt) at offset 0x12608 10896 bytes
font_02_sfnt_off00013f5c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13F5C 16792 bytes