Malicious PDF — malware analysis report

Static analysis result for SHA-256 c826f96491d7b058…

MALICIOUS

PDF

86.1 KB Created: 2021-06-29 02:42:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 055945268f57ad7c599499b9e23b5668 SHA-1: f6fb085679dd3f67bb591ea33bc8f58fc5b28701 SHA-256: c826f96491d7b058a03f658dd42ca44af39d0a85c7e3d666c4ffba9b9c6213fd
216 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by multiple heuristics and a machine learning classifier, specifically flagging it as a phishing or trojan PDF. The document body, though heavily obfuscated, combined with the 'SE_SECRET_RECOVERY_LURE' heuristic, indicates a phishing attempt to steal user credentials or recovery secrets. The numerous embedded URLs pointing to compromised CMS upload storage and disposable hosting further support this, suggesting a tactic to host malicious content or redirect users to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 7

  • Recovery secret / private key request critical SE_SECRET_RECOVERY_LURE
    Document requests recovery phrases, private keys, backup codes, or saved passwords. Requests for these secrets in a document are high-risk.
  • 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://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/p9sgofjhtoqpp1amhtlt77imrl/wifixivurolepupiguma.pdf
    • https://tangente-mag.com/img/file/41789117085.pdf
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/160885e565eff2---kobixuxi.pdf
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c40641070f6---80206962029.pdf
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/4eab9c6d766a4d1fae28e9fb0fbe40eb/vogovekit.pdf
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c0b5b02c1e0---vinijefete.pdf
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/0180e3b57660eaab467eb4095ba89f82/33215579936.pdf
    • http://aristosaigonhotel.com/uploads/files/67889306437.pdf
    • http://brenna-ski.pl/userfiles/file/4531986040.pdf
    • http://proxima-design.cz/files/file/wipixeziziwobovevuja.pdf
    • https://www.3dreamchurch.com/wp-content/plugins/super-forms/uploads/php/files/3ef8018c5cf8a93fc38e4d06d3b4c760/34112245073.pdf
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/160b2f2aa2ccd5---62914079298.pdf
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160985fe2c26fd---76545763572.pdf
    • http://host.keraladreamhomes.com/~viswabrahmathach/admin/fckeditor/editor/filemanager/connectors/php/userfiles/file/51312490573.pdf
    • http://anhuizpyy.com/upload_fck/file/2021-4-29/20210429124827251408.pdf
    • https://dgaspcsm.ro/ckfinder/userfiles/files/61986658646.pdf
    • https://monuments-msk.ru/wp-content/plugins/super-forms/uploads/php/files/581c76cd87a1dbc9acd6fd7724242a4a/56184018263.pdf
    • http://cartopack.com/Images/file/7639989633.pdf
    • https://eyestech.in/wp-content/plugins/super-forms/uploads/php/files/9g7g8flc6ss8etr085am5c2sqd/46493804308.pdf
    • http://myjobcareer.net/userfiles/file/2021062008341173499.pdf
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/160cc40b4e61ee---mifazipiwi.pdf
    • http://nutronicltd.com/userfiles/file/90623553157.pdf
    • https://www.northwoodmedical.ca/wp-content/plugins/super-forms/uploads/php/files/t0av1fkcc8olvivbacq93h63vi/makumewamimaxopusodifiduf.pdf
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b730200118e---toziwoguji.pdf
    • https://utilitydiscount.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3af55452ca---totududolotipevejegifib.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=how+to+get+saved+passwords+on+android
    • 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_off0000ed74.bin
3744ec3dcce97afef49e645b51e26f0c9e27d5bb82145703889043061683de08
pdf-font-stream PDF embedded font (sfnt) at offset 0xED74 17156 bytes
font_01_sfnt_off00011a5f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A5F 16792 bytes
font_02_sfnt_off00013276.bin
d9509224299eeea0475908e1a62c944c283212df09c9964525631f5d619503fe
pdf-font-stream PDF embedded font (sfnt) at offset 0x13276 10664 bytes