Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6f808ef23c51aed…

MALICIOUS

PDF

88.5 KB Created: 2021-08-01 10:02:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2b27a30521c5e674265c0bfa1c6f6768 SHA-1: 84cc23556251337113e5975d546f625247cd0b28 SHA-256: a6f808ef23c51aedd13db90d8e9c0440562138129731c19b56e0ef2f5f167931
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple compromised or disposable hosting sites, some of which are WordPress uploads. The presence of numerous external URIs and the ML classification strongly suggest an intent to redirect users to malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://studioindelicato.com/userfiles/files/napupesepujap.pdf
    • https://www.davidcosz.de/wp-content/plugins/super-forms/uploads/php/files/8tc0ej5hftka1aqa609b5ok9g3/wetoretudabub.pdf
    • http://bulk-supplies.com/userfiles/file/60742080148.pdf
    • https://thuaphatlaihoanghuy.com/uploads/files/zagoni.pdf
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a132fdb9131---gakolebirejezar.pdf
    • http://minerva-collection.net/files/files/jozulafurugozurapomumuso.pdf
    • http://sns.hu/_user/file/puliminukimobuwot.pdf
    • https://schmitz.cz/res/file/50610437918.pdf
    • http://artospace.com/pics/file/85975468489.pdf
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a737898f381---4774688495.pdf
    • http://xn--80affcyoc0ac1f6a.xn--p1ai/admin/modules/ckeditor/ckfinder/userfiles/files/podufek.pdf
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/46d1028b2f54a9484f7375c78d54261b/koxinuvosilosibi.pdf
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/pr41o3rjtha5mbh8djn8b1l43u/tegeturogezeloxazu.pdf
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609129d6a50be---pemimoxa.pdf
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/0912953948bf2730f5a33687a4b28bf3/samatakido.pdf
    • http://doo-san.com/userfiles/file/20210520051728.pdf
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cbefab11378---82163875952.pdf
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf0bcc9dc6---zevajolol.pdf
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/d98f4d1e50578738e9b6623939feae97/doroxesugekajip.pdf
    • https://alnahamgroup.com/userfiles/file/48175455130.pdf
    • http://nitexprofi.cz/userfiles/file/48549956918.pdf
    • https://transpack-krumbach.de/_upload_bilder/_filemanager/file/88382614090.pdf
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1609ff05c1167a---10361254080.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=how+to+talk+to+yemaya
    • 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_off0000f357.bin
f7f4e4a03f4b567c8033c5d92ca955043ff2a6ca93aec51fb2c7dbe87cae5e06
pdf-font-stream PDF embedded font (sfnt) at offset 0xF357 10088 bytes
font_01_sfnt_off000109e9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x109E9 16792 bytes
font_02_sfnt_off000121fb.bin
c70e63399dc47cfe0e6cfd1e2bd447d1b83005bebd81a7c4ab828171735124bd
pdf-font-stream PDF embedded font (sfnt) at offset 0x121FB 19360 bytes