Malicious PDF — malware analysis report

Static analysis result for SHA-256 a11b44d50cdb1791…

MALICIOUS

PDF

88.1 KB Created: 2021-08-23 17:06:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: cef393ef1858f8f2275657d38e64d586 SHA-1: 919e3d57bd2e7a028131c1696563eaeb9c32c5ad SHA-256: a11b44d50cdb1791d02b1cba5ac5f564b6a092c751d70696946ec55652ec2ba2
156 Risk Score

Malware Insights

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

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 pointing to multiple compromised CMS upload directories and disposable hosting sites, suggesting an attempt to distribute malicious content or phish users. The presence of numerous unknown URLs supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9919

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 http://atut-biuro.com/uploaded/file/viturodufoluxufenojeg.pdf In PDF document text
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/118sqvr0nrvl04iif1jgrahbd6/86267886127.pdfIn PDF document text
    • http://giaodantanthaison.com/Images_upload/files/berozodadivofanaf.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cf2fc45c0a0---82847556102.pdfIn PDF document text
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0c08486917---notubikifigepewofex.pdfIn PDF document text
    • https://marikakozmetika.hu/editor_up/85623302136.pdfIn PDF document text
    • http://www.klimavill.com//data/editorfile/83484600142.pdfIn PDF document text
    • https://zemiigori.com/uploads/file/77142524259.pdfIn PDF document text
    • https://sinhadventure.com/uploads/file/guzizo.pdfIn PDF document text
    • http://xn--80ab1a9a.xn--p1ai/sadm_files/baradoga.pdfIn PDF document text
    • http://jucal.es/images/file/56397943710.pdfIn PDF document text
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/d3fd9459e5c987e6001ffde192c66025/3384806332.pdfIn PDF document text
    • https://recrut.com/files/files/gelilolipulup.pdfIn PDF document text
    • http://schodylux.pl/userfiles/file/64844881652.pdfIn PDF document text
    • https://jiptv.nl/wp-content/plugins/super-forms/uploads/php/files/rqko0817iht36cui6fa7e5k2tn/rajarivijapovugakopoziv.pdfIn PDF document text
    • https://webtraffic.ch/wp-content/plugins/super-forms/uploads/php/files/b4ld9t6v3j8jqepnncmm32748a/kawagogadejutavajezatefal.pdfIn PDF document text
    • http://sinproval.it/userfiles/files/fapavakakup.pdfIn PDF document text
    • https://agentcctv.com/userfiles/file/60047728298.pdfIn PDF document text
    • http://zuche0551.com/upload/file/zezimorazonalisa.pdfIn PDF document text
    • https://vydavatelstvoklett.sk/userfiles/file/55161230452.pdfIn PDF document text
    • https://jgmurphy.com/wp-content/plugins/super-forms/uploads/php/files/fa697342fcc929dcad008160e4d081e3/5477855299.pdfIn PDF document text
    • http://tid.vn/upload/files/99573795439.pdfIn PDF document text
    • http://myphamlulanjina.com/upload/files/54804627299.pdfIn PDF document text
    • https://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae48d2e1c5a---20804013100.pdfIn PDF document text
    • http://ambvet-trefontane.eu/userfiles/files/55614194557.pdfIn PDF document text
    • https://xn--64-mlcufjjaii0l.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/e81701e935dbf634d7594cc050bad722/31101055746.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=everyday+use+by+alice+walker+summary+and+analysisPDF 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_off0000f3e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3E4 10892 bytes
SHA-256: 73ad67fb6372b9b9d79933be2781ed165417ae1298c13dd9c13be8a66c20efff
font_01_sfnt_off00010d16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D16 17092 bytes
SHA-256: 506ed15abab3a0afd421f5c7af6e0f37eeb68fe1c74f55f04e59f2eb3710a96d
font_02_sfnt_off00013903.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13903 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1