Malicious PDF — malware analysis report

Static analysis result for SHA-256 27d5407de350ed69…

MALICIOUS

PDF

76.9 KB Created: 2021-09-01 10:15:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 88148b8963e43a7f8f085e12fc1b0515 SHA-1: d4e6dde59555b22e3fa8c9b1971a4233ba1aa985 SHA-256: 27d5407de350ed690b7ed3d4ff0abce06fa465374703269c76cde405e119e537
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm containing numerous external URIs, many pointing to compromised or disposable hosting domains. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9954

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://muzycznescyzoryki.pl/userfiles/file/4177830577.pdf In PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c54e20f8a7---7119007129.pdfIn PDF document text
    • https://gizaviation.com/uploads/files/fabijafusasibap.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ce51d88a885---75546788154.pdfIn PDF document text
    • https://j26clean.com/upload/files/4670485756.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/16103127838355---sixemazitoxumeb.pdfIn PDF document text
    • http://logtech.cz/foto/Image/file/22017524248.pdfIn PDF document text
    • http://www.valathors.com/ckfinder/userfiles/files/diwizoritimu.pdfIn PDF document text
    • http://self119.net/upload/userfiles/2021/06/files/210610185507.pdfIn PDF document text
    • http://middlegeorgiacoinclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/160703aad798b1---panudaruxudatiwoture.pdfIn PDF document text
    • http://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/ad327ffbd262898cc9b15fe3b3204784/laxar.pdfIn PDF document text
    • http://uticachemical.com/files/upload/files/tonazugivapofuxak.pdfIn PDF document text
    • https://baodinhsolar.com/wp-content/plugins/super-forms/uploads/php/files/54923nluk2hj7vjltd06ftjo25/novagodewufowebe.pdfIn PDF document text
    • https://taksis.lv/taksis/userfiles/file/17380045637.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609f1dccef987---wepubomarasozunazosob.pdfIn PDF document text
    • https://advantagelic.com/singhania/downloads/file/91464221053.pdfIn PDF document text
    • http://helloslow.com/data/userfiles/files/64727090660.pdfIn PDF document text
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/c6d5d7c58b92bf78fde90c48306da85d/kobomigonapegiv.pdfIn PDF document text
    • http://hibertek.com/image/files/20210809_113839.pdfIn PDF document text
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a1364e697bf---51448125232.pdfIn PDF document text
    • http://familie-schiecke.de/images/file/rudaloregajokixapi.pdfIn PDF document text
    • http://steakclubhn.com/campannas/file/zafebizir.pdfIn PDF document text
    • http://pospatrans.cz/UserFiles/File/37483655547.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610832ef09d22---99035068608.pdfIn PDF document text
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/g2bs305m0d0amso217n1q9l37a/vubenajudokidexurinegok.pdfIn PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/7a524080767173c092425e90292dda47/lufunoresirevikeno.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=music+theory+fifthsPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ca39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA39 10328 bytes
SHA-256: 25051eb89fd9543be32f771533ef8f2ae65a508dbad32b85430da3085f2cb29f
font_01_sfnt_off0000e1bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1BB 16932 bytes
SHA-256: 7003185f4427f53b4d7d7f11cea6ead4040969734d66bd04ba80d98a3f766788
font_02_sfnt_off00010d52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D52 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1