Malicious PDF — malware analysis report

Static analysis result for SHA-256 8bc1307f79e51766…

MALICIOUS

PDF

82.1 KB Created: 2021-07-07 05:18:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f884eb792459826c6d756b11a70e23b9 SHA-1: 76d1366c63d679976919a2ab6625bcd76e2337e6 SHA-256: 8bc1307f79e51766f4867e536d2f21cb8b345ed7b3e7798dfdb8a84b485a3940
156 Risk Score

Malware Insights

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

The PDF file contains numerous links, many of which point to compromised WordPress sites acting as a link farm. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable binary data, suggesting the primary malicious function is the embedded link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/920a0912a3bf8801a8c76bbe7da41c11/51167943956.pdf
    • http://zelene-centrum.cz/webpagebuilder/ckfinder/userfiles/files/rupalo.pdf
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c1e46cf224c---givusawob.pdf
    • http://beamstraffic.ae/amb/userfiles/file/sepiri.pdf
    • https://uleshuzataruhaz.hu/files/file/160528132.pdf
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/72d73f325838416abe948d082ad0e0fa/57593881386.pdf
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160da1b7ccd82a---pazobumewudojapawije.pdf
    • http://mobydick-band.de/fckdata/file/5454796199.pdf
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d20592e334---jugisedogiwulaguvovotite.pdf
    • https://themodernla.com/wp-content/plugins/super-forms/uploads/php/files/5a5f5833e6dd16300b6d61580a5a1768/65136508939.pdf
    • http://huerural.com/uploads/image/files/16486885867.pdf
    • https://eatorhours.org/e-bussiness/fckimages/file/lelukaxowowasu.pdf
    • https://northstarexecutivesearch.com/wp-content/plugins/super-forms/uploads/php/files/6978c25bc831deede30cffaf4d0976f3/82110753974.pdf
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609716b606133---fopuso.pdf
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/16081829d06a0b---5055516171.pdf
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607c8ab5a0762---8341071684.pdf
    • https://www.visitrwanda.com/wp-content/plugins/super-forms/uploads/php/files/fad30d491f30e9a54378608e8dacc0e3/radigamufezuzanakupakoda.pdf
    • https://yournew.site/wp-content/plugins/super-forms/uploads/php/files/g9jfn6q2ndrltb9pufagjo3lfo/woxalodukupuj.pdf
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/g18hnt6ra8t859150qt4kbg2n4/94398589905.pdf
    • http://xn----8sbnbd9chja.xn--p1ai/userfiles/file/riratifasekogaj.pdf
    • https://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1bd414cab1---52235865807.pdf
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607748b660685---1624226288.pdf
    • https://www.marbelitesa.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9a52e5636---zokisegeporonad.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=let+it+hang+out
    • 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_off0000d937.bin
2729f02353ebefd6c70900713545c7e47e6c8070f3a2c7ea7d3283c755cb520f
pdf-font-stream PDF embedded font (sfnt) at offset 0xD937 19860 bytes
font_01_sfnt_off00010b4c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B4C 16792 bytes
font_02_sfnt_off00012363.bin
535c5783a1ee962ccfd1acfa20de6ff3df2c28d5d00124ad91b61be61e295f7d
pdf-font-stream PDF embedded font (sfnt) at offset 0x12363 10132 bytes