Malicious PDF — malware analysis report

Static analysis result for SHA-256 51d4c76ccbfe4c66…

MALICIOUS

PDF

109.9 KB Created: 2021-08-11 12:14:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9913a001db80431b4336a171aff45ea5 SHA-1: c39c5f285ae24265bda2df7aeb1f188a02501c0e SHA-256: 51d4c76ccbfe4c665346bbb474ea3f5d79b1d49011989c9dd41ddd5e85c647cd
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised CMS upload directories, suggesting it functions as a link farm to distribute or host malicious content. The presence of external URIs and the 'link farm' heuristics strongly suggest a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

Heuristics 7

  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/160febf1d875e4---4484668119.pdf
    • https://sealskinz.ru/files/file/7202380541.pdf
    • https://burkina-businessschool.com/business_school/uploads/file/35056780021.pdf
    • https://harshahometutors.com/uniformkontakt/userfiles/image/files/dirodego.pdf
    • http://thermcom.cz/userfiles/file/lavaruxipug.pdf
    • http://ruresept.ru/files/file/6954537514.pdf
    • http://ttworld.hu/uploads/content_files/files/dugitabidatuzukowijug.pdf
    • http://itnetworkconsultingsf.com/helpdesk/app/webroot/img/userfiles/files/sagozijun.pdf
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcf4f4e2c20---67646538496.pdf
    • http://wonderful-foods.net/userfiles/file/81105405354.pdf
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c056611e10a---52680452490.pdf
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/mebewovoduruf.pdf
    • http://sonnenheizungen.ch/fckeditor/editor/images/file/70186528081.pdf
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d9605e8d5a2---gexilaxaj.pdf
    • https://erdenetpost.mn/userfiles/files/66370733556.pdf
    • https://ltgtrends.com/wp-content/plugins/super-forms/uploads/php/files/b43cc1387a96a582fb438463fdfbf6a8/6488816673.pdf
    • https://digireg.nu/upload/77504572360.pdf
    • https://securityguardsupply.com/php/uploads/file/31543101407.pdf
    • https://shopinhome.com/ci/userfiles/files/77197151945.pdf
    • https://khonggiansachhanoi.vn/uploads/files/banenakosifu.pdf
    • https://aljuboori.com/userfiles/files/titek.pdf
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/798530b2200510d55328f676d2cf5314/5329865004.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=how+to+hack+tivo+premiere+no+subscription
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001482f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1482F 16792 bytes
font_01_sfnt_off00016041.bin
91eb97026546dda8f1fa4704c61be11617e2349d04881d696063e6c1aea717d8
pdf-font-stream PDF embedded font (sfnt) at offset 0x16041 17760 bytes
font_02_sfnt_off00018f45.bin
f606e84180c493d3ec94f9dcca8970806c5f4b728fe3da03bddc21ff36b8096f
pdf-font-stream PDF embedded font (sfnt) at offset 0x18F45 11068 bytes