Malicious PDF — malware analysis report

Static analysis result for SHA-256 a852f544616f89aa…

MALICIOUS

PDF

86.4 KB Created: 2021-09-18 15:43:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 8c6c36364a7c22a1add6c4b36625db7c SHA-1: f7e087b80d654bc733214f4c01613a0ca491db09 SHA-256: a852f544616f89aa8386f8b74d5f0426490cad681ac4983ee785339962638a22
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV also detecting it as a phishing trojan. The document contains numerous embedded URLs, many pointing to disposable hosting or compromised CMS uploads, indicating a link farm designed to redirect users to potentially harmful content. The presence of these links suggests an attempt to lure users to external sites for phishing or further malware delivery.

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://inprovitperu.com/ckfinder/userfiles/files/77935346806.pdf In PDF document text
    • https://charterfori.ir/basefile/charterforiir/files/65109597331.pdfIn PDF document text
    • http://bdsps.org/slbdavbatala/userfiles/file/lawupikurelutosawo.pdfIn PDF document text
    • http://russkiivopros.com/images/FCKeditor/file/nulas.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/161302fc75b2f5---7090645270.pdfIn PDF document text
    • http://phongthuydotho.vn/upload/files/zulitin.pdfIn PDF document text
    • https://revive.fashion/upload/files/luvikaji.pdfIn PDF document text
    • http://szilasfood.hu/pic_upload/files/18176458584.pdfIn PDF document text
    • http://bluelakehomestay.com/uploads/image/files/pitabupibaxejoxe.pdfIn PDF document text
    • http://lightningriskassessment.com/ci/userfiles/files/23403113060.pdfIn PDF document text
    • http://podarox.ru/public/files/bovute.pdfIn PDF document text
    • https://www.allduniv.ac.in/ckfinder/userfiles/files/15770156885.pdfIn PDF document text
    • http://eunlocker.com/Images/Editor/file/74808632644.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613abb0d946a8---regozera.pdfIn PDF document text
    • http://saddabro.com/userfiles/file/gudiwimojazi.pdfIn PDF document text
    • http://lawfirm.vn/MINH/user_files/file/zizevajovumeveval.pdfIn PDF document text
    • http://iiiemjobs.com/FCK_Editor_Images/files/47596211479.pdfIn PDF document text
    • http://simsvizag.com/admin/uploadedfiles/file///14739366966.pdfIn PDF document text
    • http://fleshlight-tw.com/userfiles/file/jiwezugokovimefukav.pdfIn PDF document text
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/1614233323d12a---rirodakabimoxutos.pdfIn PDF document text
    • https://fertilizerproductionprocess.com/d/files/24613203794.pdfIn PDF document text
    • http://candientu24h.vn/webroot/img/files/82787431447.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=android+app+for+texting+on+computerPDF link annotation
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/6086d6d7721baf89dadf2d672e22b5f0/90493203519.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_off0000ed05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED05 10932 bytes
SHA-256: b64a7f2e718bda3e8c4e112608fe88f6b1cefeb222aee906fbe18423a3ce706a
font_01_sfnt_off0001062f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1062F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011e41.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E41 17648 bytes
SHA-256: a459052a25dbf9488eac0016cd5df47b8a8658f354370842077ccc3b3323bda4