Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf5e4c49c39e3213…

MALICIOUS

PDF

95.7 KB Created: 2021-09-13 15:36:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 5713bffcd127171bd35e4c67111e6e82 SHA-1: 65f08e31d8d51cd651e95b854fc5e3af48a993fb SHA-256: bf5e4c49c39e321347879bd0cbe3fbe34db7747aecabd69e65c4f2c481706986
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple external websites, some of which are hosted on compromised CMS uploads or disposable domains. The presence of numerous unknown URLs suggests a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://hanoihome.net/img_duhoc/files/3603687838.pdf In PDF document text
    • https://www.asoriofrio.org/ckfinder/userfiles/files/4627185065.pdfIn PDF document text
    • https://binarbaidservices.com/public_html/userfiles/file/gozawosute.pdfIn PDF document text
    • https://adminico.nl/userfiles/file/lesabofekufosoforilatupu.pdfIn PDF document text
    • https://shian-jin.com/UserFiles/files/kadiki.pdfIn PDF document text
    • http://dlugopis.kbo.pl/ckfinder/userfiles/files/62176866799.pdfIn PDF document text
    • https://trieurodata.ro/images/file/senijedoninox.pdfIn PDF document text
    • http://odontoflash.eu/userfiles/files/70045530148.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613e78fde3a0d---gosegevu.pdfIn PDF document text
    • https://portalbime.com/UploadedFiles/New/file/lofokewifolorexar.pdfIn PDF document text
    • https://junona.manyel.website/images/uploads/medium/34597524108.pdfIn PDF document text
    • http://gamjagolla.com/uploads/files/68968875308.pdfIn PDF document text
    • http://medicare-darmstadt.de/bilder/UserImages/file/gogubafamusafasomar.pdfIn PDF document text
    • http://zapatosperezcabrera.com/ckfinder/userfiles/files/64929699678.pdfIn PDF document text
    • http://adirondackseafood.com/ckfinder/userfiles/files/gilije.pdfIn PDF document text
    • http://104408017.linker.tw/files/xevopunobegu.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16137bc8346e28---nuwires.pdfIn PDF document text
    • http://littleitalypizzany.com/nbloom/fckuploads/file/tigepub.pdfIn PDF document text
    • http://lsbwg.com/ckfinder/userfiles/files/20210913/0649204330.pdfIn PDF document text
    • https://ud-hobby.com/images/Upload/file/93378498189.pdfIn PDF document text
    • http://bantinnhadat.com/users/files/86280491870.pdfIn PDF document text
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613614407719e---34558065659.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=how+to+print+oversized+pdf+on+multiple+pagesPDF 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_off00010ce4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CE4 11144 bytes
SHA-256: bc2cdf5e3bdf1e19be8dc731fb55cd1219b87efa53d6f3cce5757a18850d5adc
font_01_sfnt_off000126c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126C1 19196 bytes
SHA-256: 2a26201215bb644505e15ee70dff4d13004032e4844b893852eed694787d269c
font_02_sfnt_off000158d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x158D2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1