Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7536dfd7aeb9fd0…

MALICIOUS

PDF

82.5 KB Created: 2021-09-17 19:58:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: b530c2f7e31386fbe0f8b34f20ef3943 SHA-1: d2972a65c6be97b762ddfae7bf1182f37aa8c422 SHA-256: b7536dfd7aeb9fd03c9f23257cb3770744cf6009305dab4d7bcef844ac3e8b50
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious. The presence of these links suggests an attempt to lure users to malicious destinations, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 5

  • 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://irlanc.ru/uplcv?utm_term=android+chrome+tab+groups PDF link annotation
    • https://beautifulhairstore.com/upload/files/zedufadamewuzisokezapifa.pdfIn PDF document text
    • https://stockbauer.hu/uploads/file/subajefadunugus.pdfIn PDF document text
    • http://offerseir.com/basefile/offerseircom/files/kilexirasumibo.pdfIn PDF document text
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/eff339ebd5a6f94c4a446cd46859043a/73795195824.pdfIn PDF document text
    • https://produktybhp.pl/pliki_user/File/67461909150.pdfIn PDF document text
    • http://zensushialiso.com/uploads/files/kisopatazivawatin.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16134ea648cc40---gosoj.pdfIn PDF document text
    • http://infoegrafica.com/userfiles/files/14057606173.pdfIn PDF document text
    • https://onlinendttraining.com/files/visono.pdfIn PDF document text
    • https://kcharp.com/ckfinder/userfiles/files/27590320194.pdfIn PDF document text
    • http://kabaretyimpresariat.pl/Upload/file/vivupogijidufazatoko.pdfIn PDF document text
    • http://tuvanthanhlapcongty.biz/upload/ck/files/69181568663.pdfIn PDF document text
    • https://itexpertdog.com/upload/files/90441887083.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/9u5pnn4qbgoamed5ijlgpieir3/8104048693.pdfIn PDF document text
    • http://showpelec.com/data/file/20210912_203617_355.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613abf0127218---38928684318.pdfIn PDF document text
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613155384ff72---mutipos.pdfIn PDF document text
    • http://rentbucharest.net/images/userfiles/90111314343.pdfIn PDF document text
    • http://palirna-frydek.cz/uploaded/file/lezafunowaziwu.pdfIn PDF document text
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/161346a3a7f8e3---dijokunaberudisal.pdfIn PDF document text
    • http://pincailight.com/zk/UploadFile/file/2021090712194873499.pdfIn PDF document text
    • http://zoo-foto.cz/userfiles/file/vajugagigebinatatemujarel.pdfIn PDF document text
    • http://chinamakina.com/userfiles/file/33283708993.pdfIn PDF document text
    • http://thaoduocvn.com/userfiles/image/file/29589273566.pdfIn PDF document text
    • http://phuwangnam.com/user_file/file/39130778422.pdfIn PDF document text
    • 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_off0000dd10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD10 11136 bytes
SHA-256: 2158992607fa4b0fad54f79773408f755343fc8cb6a21746735a004c542096b8
font_01_sfnt_off0000f670.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF670 18004 bytes
SHA-256: fc6bf1b2a81e3497e9aa8f3840e6b5a4333afd0f9a8df5205f5a9bddbbfe0350
font_02_sfnt_off00012482.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12482 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1