Malicious PDF — malware analysis report

Static analysis result for SHA-256 f13b170c9f4ae150…

MALICIOUS

PDF

89.0 KB Created: 2021-08-17 23:53:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6d0e0ddcc52b2104301b79f4305099fd SHA-1: 12e440f99f43491c0cd8ff019667cb0c88915abb SHA-256: f13b170c9f4ae150e4d4f5b8037d20f88acd09f71ebab8ee6d32d2b261eaa98d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links pointing to compromised CMS upload storage, indicating a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the presence of these links and the overall detection suggest an attempt to deliver a secondary payload or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098547c1c3b8---wifimixovebojamavab.pdf
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073776b47ec8---97974629594.pdf
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/160c597e2f099a---97694255531.pdf
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a8eda9cabb---53410482891.pdf
    • https://bluetact.com/ckfinder/userfiles/files/budikefetikiriwe.pdf
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16082ca7c47732---rumobewiwalitutilalojezoz.pdf
    • https://aartipalette.com/userfiles/file/miwewerefoto.pdf
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/mr1e7l7kbro18d9mumri3ldf74/71404535543.pdf
    • https://3dreamvr.com/wp-content/plugins/super-forms/uploads/php/files/2682c3a761107f6781c7799dda192917/21260657354.pdf
    • http://mwflower.com/upimagesfile///10922265914.pdf
    • http://perfectthesale.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e258ea4e11e---xotowigumitunigefetujipib.pdf
    • http://studioindelicato.com/userfiles/files/42825702678.pdf
    • https://autotrans911.com/thread/admin/uploads/file/nulagemopegenufi.pdf
    • https://ecohort.info/userfiles/files/risizudunido.pdf
    • http://ampletrekking.com/userfiles/file/wudebomodubufipu.pdf
    • https://tavio.ru/files/file/83889920443.pdf
    • http://cetinelektrik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160ac82c8d5e1b---87820993654.pdf
    • https://jjcfurnituremaker.com/userfiles/files/45388221452.pdf
    • https://samarthanamparisara.org/apadmin/uploads/userfiles/files/torotenuxurozixeliv.pdf
    • http://re-view.online/fckFiles/file/50279259141.pdf
    • https://www.charityweiss.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b626cb50f80---17645622013.pdf
    • http://seasonsblinds.com/uploads/ckfinder/userfiles/files/81047545397.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=acento+diacr%C3%ADtico+ejercicios+para+imprimir
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000de78.bin
1c5bdc01ed2d095ef08c07d40eccabf8a46d110d3fbcb083550cfd95f1137c7e
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE78 17780 bytes
font_01_sfnt_off00010add.bin
66f18be9524db0b90f05e3da990d354c6ac9e1e19a160a35f889e0de8575cd7a
pdf-font-stream PDF embedded font (sfnt) at offset 0x10ADD 16300 bytes
font_02_sfnt_off0001210d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1210D 16792 bytes
font_03_sfnt_off00013924.bin
cc4d21cc602a42b3af1f1d9064a728a2402cc3718315686602e745ca64fd49af
pdf-font-stream PDF embedded font (sfnt) at offset 0x13924 10800 bytes