Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1e4b681aa90da92…

MALICIOUS

PDF

77.5 KB Created: 2021-09-05 11:46:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2d9fde54866c1ec88d57e3e9e4a1098a SHA-1: 8a95bcbc0c0aaec741ed8ba959bae3b01cfef3b7 SHA-256: a1e4b681aa90da92fe67bf55710027445224c389aa77ca9f89d72a8cfd853ef0
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised websites or link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' confirm the nature of the links as a tactic to obscure malicious destinations.

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://almuhja.ps/ckfinder/userfiles/files/nikuvarepejenikuvuvi.pdf
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e099a937d1---sinibimikarigegifojamida.pdf
    • http://harc-ias.vn/Images_upload/files/11114910038.pdf
    • https://webbsoil.com/home/webb/public_html/ckfinder/userfiles/files/worebijiped.pdf
    • http://saamfactory.com/wp-content/plugins/super-forms/uploads/php/files/d7bb0ab6cf4eedd8260f3116aed770f6/61822088308.pdf
    • https://ms02bet.com/contents/files/62238372911.pdf
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/off53ecreldd6jfnrpfag649n7/83689308421.pdf
    • https://bisnismedsos.com/userfiles/file/73619066126.pdf
    • http://pastadimatteo.com/ckfinder/userfiles/files/jazekixewono.pdf
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/160f2587c2dd11---72853279345.pdf
    • http://www.tekkoo.net/images/library/File/56785452381.pdf
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609a36a8dfedc---fewodufarap.pdf
    • https://misbahelmudii.org/ckfinder/userfiles/files/4850740778.pdf
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/cd4bd3cc3b33516715ade9c373f01689/zepesixopa.pdf
    • https://almondzwealth.com/administrator/imagetemp/file/55921329055.pdf
    • https://highrise.pl/file/girowulejod.pdf
    • http://hoinhikhoavn.com/img/files/29291545723.pdf
    • http://artpolinakuzina.ru/pict/file/gunexurej.pdf
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608db48e409d0---gogewogokejoxozuz.pdf
    • http://ippon.lv/uploads/File/22641383196.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160db991cc3fe3---vazuwutejufepuset.pdf
    • http://porpora.info/imagenes/imagenes_contenidos///powupiragudarenixomabip.pdf
    • http://crescentcarpets.com/userfiles/file/gomutibi.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=hribar+worksheet+week+12
    • 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_off0000cb9f.bin
9e919690aba51db6967b23594fb1803d0485fbf1ecda1439bc043968ea53cab1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCB9F 17244 bytes
font_01_sfnt_off0000f820.bin
3b16f55ce9d6020b404612a44b12a9031d569053c857f8ecef3cfebca124a285
pdf-font-stream PDF embedded font (sfnt) at offset 0xF820 10536 bytes
font_02_sfnt_off00011074.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11074 16792 bytes