Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4790e0ad3039537…

MALICIOUS

PDF

85.0 KB Created: 2021-09-04 15:07:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 167f4b483cac34f50c58de6cadd9f456 SHA-1: 5f26076ac2bf4bbe22299732917c08872418d959 SHA-256: a4790e0ad30395370dfab865d5a3a20d75c72616f26edc3aa89602835a3f87b0
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, embedding numerous URLs that point to compromised CMS uploads and disposable hosting. These links likely lead to phishing pages or further malware downloads, aligning with a spearphishing attachment attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://pbchistoryonline.org/uploads/file/38675820649.pdf In PDF document text
    • https://thesaddlebank.com/wp-content/plugins/super-forms/uploads/php/files/fv2cjf6nb85h9gmvet4jugq9bh/63292479359.pdfIn PDF document text
    • http://braghieriarchitettura.com/userfiles/files/3890222536.pdfIn PDF document text
    • https://www.kbstephens.com/wp-content/plugins/super-forms/uploads/php/files/d0deec9bd4bf0bb3d11ec6f5ba768d28/dorunejunilanuwufig.pdfIn PDF document text
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/1607d0c5c3be36---bikozanutovoda.pdfIn PDF document text
    • http://mqskin.com/luutru/files/noxipi.pdfIn PDF document text
    • http://qunjl.com/userfiles/files/39448396220.pdfIn PDF document text
    • http://studiosantomauro.it/userfiles/files/tudis.pdfIn PDF document text
    • https://monyetjoget.com/contents//files/72367229980.pdfIn PDF document text
    • http://aircond.md/upload_fck/file/wegumebititalonovazera.pdfIn PDF document text
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608922d318101---38362865619.pdfIn PDF document text
    • http://centronegozi.com/public/pimomowowuxeguzavaj.pdfIn PDF document text
    • http://www.orhancoskun.com/wp-content/plugins/formcraft/file-upload/server/content/files/160888644638ec---50254014126.pdfIn PDF document text
    • http://spamsmsgiare.com/media/ftp/file/1914598375.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/16103184f486b1---29222416684.pdfIn PDF document text
    • http://jiendurancecoaching.com/ckfinder/userfiles/files/wenavobidi.pdfIn PDF document text
    • https://eguiders.com/uploads/64499725307.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160b999f16ed0b---monasewodaradodebixol.pdfIn PDF document text
    • https://partroyfuneralhome.com/partroy/assets/file/47551450279.pdfIn PDF document text
    • http://svaz-podnikani.cz/files/file/xiniwomukif.pdfIn PDF document text
    • https://cosalesrep.com/wp-content/plugins/super-forms/uploads/php/files/cdf0a08001e8cafb9910a6654abc355c/metaxe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=syr+lex+plus+10+connect+pdfPDF 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_off0000e0dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0DC 10924 bytes
SHA-256: 0ba66ac2f0bb3104b85006268f4e7f0a4d65a569f60c1faa9b455be5c8dfaa6c
font_01_sfnt_off0000fa5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA5D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001126f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1126F 19352 bytes
SHA-256: 479e2dcf50fe11f35f8aa311ea6541daaa29e9aa92f8485c61fa392dd5b3e823