Malicious PDF — malware analysis report

Static analysis result for SHA-256 628735157c68808b…

MALICIOUS

PDF

83.9 KB Created: 2021-09-07 19:44:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: ce1f74359597df90c68888aa4a57b6e5 SHA-1: 2f37705212f8c6b593952173206a9e2a1decad84 SHA-256: 628735157c68808baf9efcc10dd034cd43dd66845bce3cf64a1df55a0ae189b3
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites and other domains, likely serving as a distribution point for further malicious content. The presence of multiple external URIs and link farm heuristics strongly suggests a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 6

  • 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.
  • 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://queure.ru/uplcv?utm_term=que+son+los+gases+de+efecto+invernadero+pdf PDF link annotation
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090060e66ae7---javebilupi.pdfIn PDF document text
    • http://alexhofford.com/temp/files/file/lupukivotizupozeniwune.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/160b0b8167745d---zenikunerigix.pdfIn PDF document text
    • https://estoniapools.com/contents/files/54810992441.pdfIn PDF document text
    • http://terapeutickemasaze.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16092069b4045a---gonez.pdfIn PDF document text
    • http://stalmont.eu/userfiles/file/94004113722.pdfIn PDF document text
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/oc8pumohs0jhpdfs2rltlhu780/5110068765.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607734116e1c6---teropojadoz.pdfIn PDF document text
    • http://arc-en-cielproduce.com/ckfinder/userfiles/files/kotofenefotidadigama.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160b773a627494---64854822059.pdfIn PDF document text
    • http://dioblina.eu/userfiles/file/30254598418.pdfIn PDF document text
    • http://zulassungsservice4you.de/bilder/file/67838083799.pdfIn PDF document text
    • http://indago-rovigo.it/userfiles/files/73788995690.pdfIn PDF document text
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/86bdfd26169e9ecbe46dc792ae477bb7/89160636169.pdfIn PDF document text
    • https://cortemadera.com/wysiwygfiles/file/90608235170.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c44a34826f3---zamubikerekamituvowuto.pdfIn PDF document text
    • https://history.tlshaa.org.tw/ckfinder/userfiles/files/najatazapejez.pdfIn PDF document text
    • http://mitsubishilongbien.vn/images/ckeditor/files/29855476445.pdfIn PDF document text
    • http://women-for-marriage.com/ckfinder/userfiles/files/gorobuxiropanit.pdfIn PDF document text
    • https://magnificenttreks.com/userfiles/file/31930424627.pdfIn PDF document text
    • http://miskolciharsona.hu/pictures/file/33023913258.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/02arsuf62goso9nvrrq30e41p7/16952354050.pdfIn PDF document text
    • http://all-pass.com/folder/editor/file/xuzodixofelowededesipugoz.pdfIn PDF document text
    • http://trivio.it/userfiles/files/mexoxorewafugatuvojil.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_off0000dfc0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFC0 11020 bytes
SHA-256: fe5a9b199d0b6e4712819d4d6a44b7a868308c64b9c81d5cd38b2d0c18f33ceb
font_01_sfnt_off0000f974.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF974 19088 bytes
SHA-256: d80a20cea85f35003050b3222a4cd912f9c1f1138fbcdee6a098ce9c2287adcf
font_02_sfnt_off00012a1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A1C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1