Malicious PDF — malware analysis report

Static analysis result for SHA-256 a57acf10a99d5713…

MALICIOUS

PDF

85.4 KB Created: 2021-07-09 01:27:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f44cf5d14f9cf2cba99f180d1980c35e SHA-1: 069b3dd188f8f4204f173e8281ffe064fbf11fa8 SHA-256: a57acf10a99d57134d2121dfbd9a4e7d9e80072992e075dd810c125f65017bb9
156 Risk Score

Malware Insights

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

The PDF was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, with many embedded URLs pointing to external resources, some hosted on compromised WordPress sites. The primary purpose appears to be directing users to potentially malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://hoangnamjsc.com/upload/files/78319177286.pdf
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/16078a289e83e8---32323254024.pdf
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/160cb93fabc50f---newatitikaxalogojonovu.pdf
    • https://houstoncoinshow.org/FCKeditor/file/56494995894.pdf
    • http://weforyou.it/userfiles/files/nonebojudebun.pdf
    • http://afghansolar.com/userfiles/file/54764224166.pdf
    • https://mfdesign.hu/files/file/gikupape.pdf
    • http://midel.me/userfiles/file/nisifetumoloj.pdf
    • https://www.travelticket.com.au/wp-content/plugins/super-forms/uploads/php/files/i4o51d8g5eccp9bv5ut3g3cohs/60233676230.pdf
    • http://sherwoodchambergolf.org/ckfinder/userfiles/files/93980342001.pdf
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160904cbb765e9---tegododaba.pdf
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1609cfc7c916e5---baxuwakafosodiz.pdf
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/39b0fc040bc66f0fc85c62b4a4f62214/toxofevijesetagamodenosa.pdf
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/902973cb72ab1ef8446d485a1fbd44ba/rarasekosisow.pdf
    • https://etonbio.com/newsLetters/images/file/simugazefuxodagujimenowex.pdf
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/v9pqmc2in31rfq9u2ok8jf7ght/bofajerapupiwelurubogodi.pdf
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/8d8b2bf0df09cfdba02409b5c0ae3386/68525788123.pdf
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/160893ffa52582---53081277286.pdf
    • http://fw-simple.com/uploads/files/darefupopaxizarusim.pdf
    • https://247christianity.org/fckeditor/userfiles/file/977163371461622114497.pdf
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608d2be84ca79---butogeguxigin.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=you+are+beautiful+person+quotes
    • 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_off0000ea1a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA1A 16792 bytes
font_01_sfnt_off0001022c.bin
636f1bec79ec47c2b69798d690232b54727cd3ef14451119bd0c50576d19ebb9
pdf-font-stream PDF embedded font (sfnt) at offset 0x1022C 17036 bytes
font_02_sfnt_off00012e88.bin
3f892036a484d111b08042e5bf41aefa7050d008e7ece3c4269aff6c061c7ec9
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E88 10720 bytes