Malicious PDF — malware analysis report

Static analysis result for SHA-256 61c8b1a164a3b192…

MALICIOUS

PDF

82.4 KB Created: 2021-09-16 12:19:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 54074397ee8c21f23842b69265032fca SHA-1: d1631c0c35068eaf5ee466fc36a2ccfc679056e4 SHA-256: 61c8b1a164a3b1928be9cff84ae07f350ff2cd234980248fc8eca7a02cd122e1
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to compromised CMS uploads or disposable hosting, suggesting it functions as a link farm. The presence of these links, combined with the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic, strongly indicates a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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://mama-light.net/business_school/uploads/file/80928871974.pdf
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f3a55d1f14---mejanizavobiguvosaso.pdf
    • http://omonetach.pl/foto/ilustracje/file/gusuvawanenegaseg.pdf
    • https://www.informacion-indoorclub.com/boletines/img/file/51524054666.pdf
    • https://mancomunidadvaldizarbe.com/userfiles/files/45827129386.pdf
    • http://purepassion.pl/userfiles/file/22288570809.pdf
    • https://functionalmovement.gr/wp-content/plugins/super-forms/uploads/php/files/462b3fbed618a99afe0b0aab135b755d/387418411.pdf
    • http://smolensk-bakaleya.ru/userfiles/file/peramenivefidetidopo.pdf
    • http://xn--nellieskche-0hb.de/userfiles/file/80411910817.pdf
    • http://fotografieindex.nl/images/uploads/sidowalofesuxubomaxe.pdf
    • https://catbasailing.com/upload/fck/file/59321506485.pdf
    • https://vietnaminsight.biz/ckfinder/userfiles/files/sipasezu.pdf
    • http://pathtojanna.com/userfiles/files/85441796790.pdf
    • http://www.sevenchurchestour.net/seven/wp-content/plugins/formcraft/file-upload/server/content/files/1612f06fc2066f---purelalajowagimeme.pdf
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/b4f4rpc09bmfl3kc3mmep31ddb/61496567989.pdf
    • https://ibericadearmerias.com/file/gijajafafuratifekegev.pdf
    • http://mutitar.com/user_img/files/39573836774.pdf
    • http://elosc.com/upFile/file///ITX202109110306396275.pdf
    • http://www.oomewatersport.nl/upload/files/55935104173.pdf
    • http://lgassociates.in/uploads/988440140.pdf
    • https://bdblue.com/ckfinder/userfiles/files/tavivebeperari.pdf
    • http://postelezmasivu-olomouc.cz/ckfinder/userfiles/files/fobekubilevavuvoxa.pdf
    • http://araratmebel.ru/img/file/53443384108.pdf
    • https://maria-galland.ru/files/file/35894045131.pdf
    • http://another-partner.morefriendship.com/upload/files/fekemopetidu.pdf
    • http://4998horo.gmmwireless.com/contents/files/pukatunenewelut.pdf
    • https://iphonerepairservice.nl/app/webroot/files/userfiles/files/72831053904.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=amazon+prime+app+apk+for+android+tv
    • 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_off0000dab4.bin
bcaa4c36994fca5927aeda7def23d48b2e96e8cba883421486da5e305b3b1282
pdf-font-stream PDF embedded font (sfnt) at offset 0xDAB4 18532 bytes
font_01_sfnt_off00010b62.bin
5757574e60747fe63ec66ac729e8e0c9034f79223818c3ca29cd75a9ff93e260
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B62 10644 bytes
font_02_sfnt_off000123cb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x123CB 16792 bytes