Malicious PDF — malware analysis report

Static analysis result for SHA-256 1791a3c2cb8367b0…

MALICIOUS

PDF

79.9 KB Created: 2021-09-17 10:28:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 86d3c8d24ce795b95357af6a7a582731 SHA-1: 3352a021938d1d044d63dd32b1c77ebb389cc7c3 SHA-256: 1791a3c2cb8367b085e3ff435fdabcef2f10cacda4ff07727374ed94ac51ceca
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as a malicious PDF by ClamAV and an ML classifier. It contains numerous external URLs, many of which are hosted on compromised CMS platforms or disposable domains, suggesting a link farm or phishing lure. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this. While no scripts were explicitly extracted, the nature of the URLs and the PDF format itself often implies JavaScript execution for redirection or exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://cructi.ru/uplcv?utm_term=lego+star+wars+tcs+android+apk PDF link annotation
    • http://gruppocreta.com/userfiles/files/pekukugema.pdfIn PDF document text
    • http://divorce-difficile.fr/userfiles/file/gebatapifenokuzojurizuw.pdfIn PDF document text
    • http://embody.box8websites.com/ckfinder/userfiles/files/gufowijetagetuz.pdfIn PDF document text
    • https://manenshop.com/upload/files/49832981597.pdfIn PDF document text
    • http://capthepcongtrinh.com/uploads/news/files/4439471874.pdfIn PDF document text
    • http://xaydunglenguyen.vn/upload/files/9307cd.pdfIn PDF document text
    • http://symbioticlifetech.org/attfile/fckimg/file///20210905103854_494409857.pdfIn PDF document text
    • http://cpgny.com/userfiles/files/61904892578.pdfIn PDF document text
    • http://www.pataniforum.com/admin/jquery/ckfinder/userfiles/files/19901374141.pdfIn PDF document text
    • http://maremio.ru/admin/ckfinder/userfiles/files/bibitufelivub.pdfIn PDF document text
    • http://trieuduong.com/images/Download/71093613059.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613146d1bc3ce---31266670993.pdfIn PDF document text
    • http://sake-tori.com/images/library/File/10806321201.pdfIn PDF document text
    • https://hv2barrier.com/application/third_party/ckfinder/userfiles/files/75524478626.pdfIn PDF document text
    • https://butchercurnow.com/img/shop/contents/18873803935.pdfIn PDF document text
    • http://xyr59.com/filespath/files/20210903152138.pdfIn PDF document text
    • https://johanbjerke.se/userfiles/file/bodulajutupe.pdfIn PDF document text
    • http://oxigensupplies.com/shipinc/userfiles/files/xosenasudi.pdfIn PDF document text
    • http://zehanbiopharma.com/upload/files/pulefugisa.pdfIn PDF document text
    • http://cualuoiskydoor.com/webroot/img/files/rokeramulevad.pdfIn PDF document text
    • https://www.officinadelgustoroma.com/wp-content/plugins/super-forms/uploads/php/files/5a91386ff4e463c6a70051cc2d6305e6/toparapofabanunizinuni.pdfIn PDF document text
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/da6030603721d2b4f0f201946bfc566d/xurunaki.pdfIn PDF document text
    • http://mrcookie.tw/upload/editor/file/121255216441.pdfIn PDF document text
    • http://rajskiewakacje.pl/userfiles/file/debugodobibiz.pdfIn PDF document text
    • https://capecoralliving.com/media/file/dakuxefarakuveg.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_off0000c8d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8D8 22316 bytes
SHA-256: a88ee556a7567b15b58d798d04c7526c087a36f40b42b897981bd9ae5cfed6db
font_01_sfnt_off00010160.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10160 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011977.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11977 10776 bytes
SHA-256: d33ddaaf7242cb8a237dcc277854b2cf9b6c95ab3149ca75127b2a12ca645bd4