Malicious PDF — malware analysis report

Static analysis result for SHA-256 f21385d3fc296fd1…

MALICIOUS

PDF

76.6 KB Created: 2021-10-06 22:30:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 3d6764f49d3034b07c935771e26d6423 SHA-1: 720a4f76243b547879e3b4565320981dfc3db1a4 SHA-256: f21385d3fc296fd144572937aacf51479375b758447ee4251d8b1454c9f72f1d
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, specifically flagged as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The primary purpose appears to be directing users to external, potentially malicious sites, consistent with phishing or malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://gadd-asso.org/userfiles/file/karimuwifixetawemeder.pdf In PDF document text
    • http://hexindechem.com/upload/files/pizogedab.pdfIn PDF document text
    • https://egyptsuntours.com/userfiles/files/63310702324.pdfIn PDF document text
    • http://tareeapartment.com/user_img/files/90277139156.pdfIn PDF document text
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ed80bd4894---xesafive.pdfIn PDF document text
    • http://jsqnchem.com/upload/files/kulekadurorigutugopus.pdfIn PDF document text
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/161413d9d3536b---vodixogoragabif.pdfIn PDF document text
    • http://ebus.cn/up_file/file/muniw.pdfIn PDF document text
    • http://mylodge-naoshima.com/images/blog/file/14484220536.pdfIn PDF document text
    • http://telegid.tv/userfiles/file/87847158470.pdfIn PDF document text
    • https://discovercefalu.it/_data/images/file/juwadibimotoverexur.pdfIn PDF document text
    • https://bkairconditioner.cloud4demo.com/uploads/files/kasikavegitaleluwi.pdfIn PDF document text
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16159f8463cb0a---76551441904.pdfIn PDF document text
    • https://unitedfightalliance.jordanadams.com/ckfinder/userfiles/files/82277431913.pdfIn PDF document text
    • http://awkontrakt.pl/ckfinder/userfiles/files/pobatiwefelakokodojixewut.pdfIn PDF document text
    • http://startmatbaa.com/userfiles/file/vusunuruburomegewisis.pdfIn PDF document text
    • https://digiconelectronics.com/media/25344010293.pdfIn PDF document text
    • https://yennenga.org/business_school/uploads/file/73913291603.pdfIn PDF document text
    • https://jamuiboe.com/webroot/upload_media/fipalajujibaviraruxet.pdfIn PDF document text
    • http://shopcode.ru/uploads/file/kemipogobumurikos.pdfIn PDF document text
    • https://tanhoaphat.vn/userfiles/file/norosabalalulurofezo.pdfIn PDF document text
    • http://bamila.vn/luutru/files/19510937152.pdfIn PDF document text
    • https://hashtag.school/userfiles/file/89775366034.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=st+clair+countryPDF 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_off0000c783.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC783 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000df95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF95 18016 bytes
SHA-256: 942278fafef229f3f2942e5c2dfe9cc726f4a066d9ae905cd2259ac93775c5e7
font_02_sfnt_off00010e14.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E14 10212 bytes
SHA-256: 29f6e824eadc39a59a3914e9872098c9654c4f7d82cd7789217000c51e2b9fc9