Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4c2ba077a9ec573…

MALICIOUS

PDF

89.7 KB Created: 2021-07-01 15:18:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 8210a1bc85bbd488c20050fd5d10b27c SHA-1: 70a7309233be0879db04bb4d5ff75d4d1d76284b SHA-256: a4c2ba077a9ec573ee4183b23a8449b89879d35af5536f6cad822cbce88216a2
192 Risk Score

Malware Insights

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

The sample contains embedded JavaScript, which is often used to exploit PDF vulnerabilities or redirect users to malicious sites. The presence of numerous links to potentially compromised CMS upload directories and the ML classifier's high confidence score indicate a malicious intent. The document likely serves as a lure to download a second-stage payload, as suggested by the 'SE_DOWNLOAD_BUTTON' heuristic.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 9

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) or Microsoft license-boilerplate documents that carry no urgency or charge/dispute escalation.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://koovappadyscb.com/ckfinder/userfiles/files/nitaxumupuvobawitipes.pdf In PDF document text
    • https://watosaphotography.com/app/webroot/userfiles/files/20210626_011433.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/1606f4f54d2019---73197795892.pdfIn PDF document text
    • http://shiinamotors.com/js/upload/files/12014357991.pdfIn PDF document text
    • https://bd-sokolovska.eu/userfiles/file/45939254639.pdfIn PDF document text
    • http://vrtaspol.cz/klienti/devel/sneznerolby.cz/ckfinder/userfiles/files/23481427289.pdfIn PDF document text
    • https://gdr.co.il/wp-content/plugins/super-forms/uploads/php/files/db2a00984f5a56c92431ce07591205fd/62721712448.pdfIn PDF document text
    • http://etasystem.net/userfiles/files/punototav.pdfIn PDF document text
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/a3c8d1261f8e25b188226a1a149300dc/vetexitubuk.pdfIn PDF document text
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6594d9b7f1---82961691147.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a1453373800---jetebirubukirabanerotena.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160755170a7819---28591218941.pdfIn PDF document text
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c94b68b9703---paripuginazesasiwun.pdfIn PDF document text
    • https://consurs.ro/ckfinder/userfiles/files/bojukomepibumotomo.pdfIn PDF document text
    • http://cnokorea.com/userfiles/file/56638075953.pdfIn PDF document text
    • https://edu-mate.kr/_UploadFile/Images/file/40503834519.pdfIn PDF document text
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/a5bk5dm8ti470huihsd8stuvuj/37672742952.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609801c88742b---68972359215.pdfIn PDF document text
    • https://gertiesbloomers.com/kousumi/nulook/upload/fckimages/file/kixapatutazo.pdfIn PDF document text
    • https://action-roofing.com/wp-content/plugins/super-forms/uploads/php/files/69b9ff9761e576cec4d8f1d6940c6edb/kizokuvutix.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a962f1c9492---votuwodese.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1607aa6da634b3---43823664690.pdfIn PDF document text
    • https://autoteam.in/ckfinder/userfiles/files/77673952189.pdfIn PDF document text
    • https://benchmarktransitions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae7dbfbc24b---95677913201.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=book+my+appointmentPDF 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_off0000fae5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAE5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000112fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112FC 10356 bytes
SHA-256: 713559d21fa74fb582b223402efc454db1c27c6acc78f68b260387609b4cb36d
font_02_sfnt_off00012a6c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A6C 18184 bytes
SHA-256: 44e6b790dd223326aa12aee032a5ace970d25dcf33ba72a2f02d6d3c049e2bb2

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