Malicious PDF — malware analysis report

Static analysis result for SHA-256 a72c441edcb3604e…

MALICIOUS

PDF

84.9 KB Created: 2021-09-11 13:17:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: e525e6ea556d8ec983fd629122885fa7 SHA-1: ff911ac40bd368b464c165c12ac772c1a1468e26 SHA-256: a72c441edcb3604eb29c3d5d97174f50925befd6a06ca73df1b7e874a58be92d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with several URLs pointing to compromised WordPress upload directories, suggesting a phishing or malware distribution scheme. The embedded URLs and the nature of the heuristics strongly suggest the document is designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://smidgel.ru/uplcv?utm_term=exploration+games+android PDF link annotation
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/1612feaa19914d---gukofutavapafedalu.pdfIn PDF document text
    • http://signauction.net/userfiles/file/75314049474.pdfIn PDF document text
    • https://weekendtripskolkata.com/userfiles/file/votuziluzulebanevuz.pdfIn PDF document text
    • http://startent.ru/SITE/files/editor/file/13616784598.pdfIn PDF document text
    • http://w-mill.jp/images/file/21678820177.pdfIn PDF document text
    • https://zebcom.in/userfiles/file/jilaxisanefujoraji.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/161311d1508570---45653466383.pdfIn PDF document text
    • https://schmitz.cz/res/file/siluguziwewukigagekezer.pdfIn PDF document text
    • http://primebrokeragetx.com/ckfinder/userfiles/files/pujalatewafumulixemalij.pdfIn PDF document text
    • http://www.niceresidence.net/image/upload/File/xofaduxamu.pdfIn PDF document text
    • http://graviroz.hu/ckfinder/userfiles/files/lusifikodedujolaz.pdfIn PDF document text
    • http://wonikqnc.com/upload/editor/file/1631238536.pdfIn PDF document text
    • http://bakefruit.com/uploads/files/202109100431193358.pdfIn PDF document text
    • https://hunde-katzen.at/soubory/devijawan.pdfIn PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/161353e3b88e8c---gepubomimulonafokumip.pdfIn PDF document text
    • http://phamtrangia.com/upload/files/vepawazotugiziwetujiradi.pdfIn PDF document text
    • https://servicepapik.ro/files/36232289645.pdfIn PDF document text
    • https://suacuacuontoanphat.com/upload/files/ragorafekerapasuri.pdfIn PDF document text
    • http://nghiencuuykhoa.com/uploads/userfiles/file/debuzo.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/derisiva.pdfIn PDF document text
    • http://xn--12cm8caae5d9a0a0a1dxk6dd.com/user_img/files/jaxadopuwetujur.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/161306142720ef---64746972293.pdfIn PDF document text
    • https://wic-net.com/userfiles/file/15285305432.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_off0000eaa6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAA6 10820 bytes
SHA-256: e16db2f53860a205721b7d4c311214f239d941db27a1090dff1ce23cb492be15
font_01_sfnt_off0001035c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1035C 16588 bytes
SHA-256: c4c7b7150359094345b29f20271849433cb9bf45c15040788eba78352a584cec
font_02_sfnt_off00012e04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E04 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1