Malicious PDF — malware analysis report

Static analysis result for SHA-256 c80f52685278d09c…

MALICIOUS

PDF

71.0 KB Created: 2021-09-09 15:04:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3b3096e30b49ade5c129436328157ad9 SHA-1: 592a7aa29b3ad0cc2d829697807881ad7ede22b1 SHA-256: c80f52685278d09cf286dc0621ee8b156df5ab9e872ffb28f2adb6c6bc0edf00
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm or redirection scheme. The ML classifier strongly flagged this PDF as malicious, and heuristics suggest it's part of a link farm designed to manipulate search results or distribute further content. No scripts were extracted, but the structure and URL patterns are indicative of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://chinazzjx.com/d/files/sexugopimasejitojamudo.pdf In PDF document text
    • http://inkjetartandimage.com/Uploads/file/supurepi.pdfIn PDF document text
    • https://motty-etai-sharon.com/files/files/jides.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ea08a38a51---84974984790.pdfIn PDF document text
    • https://vientangluc.com/upload/files/6629424418.pdfIn PDF document text
    • https://dom4m.lv/userfiles/files/kuduguronomuxodaparaviso.pdfIn PDF document text
    • https://mogilew.ru/userfiles/file/44123896260.pdfIn PDF document text
    • http://betheaskssd.com/flash/betheaskssd.com/file/kusutudulogexuzawunolot.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137a467170bc---87636167065.pdfIn PDF document text
    • http://landroverbh.com/ckfinder/userfiles/files/famitufuxukanagujatunugi.pdfIn PDF document text
    • http://maihome.hu/admin1/file/gezikolineziwapur.pdfIn PDF document text
    • http://mispuntossaga.com/campannas/file/dilif.pdfIn PDF document text
    • https://perfecthospitals.org/FCKeditor/file/mazafanokurilowenitigidin.pdfIn PDF document text
    • http://www.wcd.com.tw/ezadmin/ckfinder/userfiles/files/kedoruxutikapibidaxev.pdfIn PDF document text
    • http://olgapolyakova.com/files/files/gawunuvetamo.pdfIn PDF document text
    • https://www.olympusnorge.no/wp-content/plugins/super-forms/uploads/php/files/8dkmplbjfv4bcgrtr83r83d2bd/movekenelekuwozezo.pdfIn PDF document text
    • http://dakov.hu/_user/file/69130819667.pdfIn PDF document text
    • https://pro-biomed.com/admin/userfiles/file/litimigobavido.pdfIn PDF document text
    • https://ou-ravda.com/ckfinder/userfiles/files/zepusadazesojigamufij.pdfIn PDF document text
    • https://kiptep.ru/file/81706533556.pdfIn PDF document text
    • http://ekorepetycje.eu/Upload/file/sufupegemegatexap.pdfIn PDF document text
    • http://xn--66-6kc8bfmkmjd.xn--p1ai/admin/ckfinder/userfiles/files/kipodutigikune.pdfIn PDF document text
    • https://probidjp.com/ckfinder/userfiles/files/20210909_073032.pdfIn PDF document text
    • http://bkm-market.net/userfiles/file/35139578780.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=hentai+games+free+apkPDF 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_off0000b552.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB552 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cd64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD64 15956 bytes
SHA-256: faacac3d5c2caab6c9e062d814ea372c1926c47c4b51a1ecf3217ac15112606b
font_02_sfnt_off0000f678.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF678 10616 bytes
SHA-256: 8bcaf6f2bf39799e7f7521cf0ba8c019c4c1f15a9d06a87d309b3acfa4e5e38d