Malicious PDF — malware analysis report

Static analysis result for SHA-256 aef31cd6d34412ea…

MALICIOUS

PDF

87.4 KB Created: 2021-07-17 15:55:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9d9ba3cb2cb1948f3195581e8fe27709 SHA-1: b6d196729d5befa67a86632ef0d8ba0757c3992d SHA-256: aef31cd6d34412eaf4989b4f7d9e0f0fbf62836da7da92628c5b40a36ea9d828
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised CMS uploads and disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. No scripts were extracted, but the presence of a link farm is sufficient to classify this as a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

Heuristics 6

  • 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.
  • 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://eslms.com/userfiles/file/wemodekefokowagudusej.pdf
    • http://jnnycc.org/userfiles/file/jivubapadugilasag.pdf
    • http://sosonomo.com/ckfinder/userfiles/files/pulemedubejisanokopun.pdf
    • http://richmediahouse.com/admin/uploads/file/39555631081.pdf
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160827ed8c3b77---tivafarez.pdf
    • https://big-affaires.com/img/pics/files/nizefanusegosefe.pdf
    • https://shared401k.com/wp-content/plugins/super-forms/uploads/php/files/e8266e6ed3900781464f664be47b1429/bajebutugenodiku.pdf
    • https://iguanapools.com.au/wp-content/plugins/super-forms/uploads/php/files/tq0ntuc9ad1kol941n203pbsbv/gitukenidegakawumumibubok.pdf
    • https://hashtag.school/userfiles/file/861730821.pdf
    • https://destockbaby.com/ckfinder/userfiles/files/dexefenavuxozidum.pdf
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/160847f926f278---42053383642.pdf
    • https://hafa-verein.de/wp-content/plugins/super-forms/uploads/php/files/059f2b72bec6689a215c418b7c889bc3/ponisosapirulufogabopixo.pdf
    • https://catbasailing.com/upload/fck/file/94838976130.pdf
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1607045a9cf5c4---78632497913.pdf
    • http://www.cerathai.com/image/upload/File/59598401641.pdf
    • http://sklepjola.pl/userfiles/file/10098025945.pdf
    • https://www.parkgest.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16087ba5c7e7d7---guserimew.pdf
    • http://humanitool.ru/userfiles/file/godedanojuvakupuma.pdf
    • http://hocikto.info/userfiles/file/wixelulam.pdf
    • https://abe-rdc.com/userfiles/file/97602500034.pdf
    • https://choiceenergynetwork.com/wp-content/plugins/super-forms/uploads/php/files/4181a658a1628d1ac67f81b95878f843/goratajavugixe.pdf
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16075f763c92b7---bofefapazukonotovolukak.pdf
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/r8stn6d3vl6vbr1pbnu9kt3lto/xogimiso.pdf
    • http://allaboutdowney.com/userimages/kejegiparejanefaj.pdf
    • http://rollfactorytogo.com/uploads/files/nutegelexokosu.pdf
    • http://lilit-realty.com/wp-content/plugins/super-forms/uploads/php/files/pd8si4egmmuunhh995c914fq02/27758126513.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=is+hydrogen+a+element+compound+or+mixture
    • 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_off0000eeb4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEB4 16792 bytes
font_01_sfnt_off000106cb.bin
97d96a896f7eff6ee30980a48fc2a967ff64d36265ccec472e9c40b38242ac15
pdf-font-stream PDF embedded font (sfnt) at offset 0x106CB 11228 bytes
font_02_sfnt_off000120b6.bin
7cd7880ed67be86f4f15bdd13332952665223aa166c0cb4664e3e34e131500f2
pdf-font-stream PDF embedded font (sfnt) at offset 0x120B6 18540 bytes