Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1df81aed0d18837…

MALICIOUS

PDF

81.8 KB Created: 2021-09-15 00:03:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c9550d9e04dcd07263a1f1aa51700a33 SHA-1: b0aaba485a0304c87d1d0f6225902ca5978b41ef SHA-256: b1df81aed0d18837e14112cbbc1597d1e4bf4c9b4dd93f5a570d4a0d078f62c7
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which point to disposable hosting or compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The presence of a link farm suggests an attempt to direct users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://pistant.ru/uplcv?utm_term=macro+clicker+android
    • http://fuzoku-kyujin.jp/ckfinder/userfiles/files/mopulewasof.pdf
    • http://yamamatoen-wanwan.jp/ckfinder/userfiles/files/34014976430.pdf
    • http://algarestofos.pnh.pt/js/ckfinder/userfiles/files/febumajutudesox.pdf
    • http://druckmaschinenservice.com/uploads/fce/files/xilubib.pdf
    • http://thuaphatlailongthanh.vn/upload/contentFile/minhchau/file/munojadifapewexipux.pdf
    • http://martonaroniskola.net/userfiles/file/24806022922.pdf
    • https://classconnbio.com/img-jacson/files/63292228393.pdf
    • http://eviljoy.com/UserFiles/File/52686927431.pdf
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/hos6lhurirs4ua2fbnckem8c53/40264185616.pdf
    • http://wdnederland.nl/file/12985449195.pdf
    • http://swvocal.com/data/se2/file/rapibevabapitesafixiso.pdf
    • http://khachsanmyngoc.com/upload/files/basovelogarefi.pdf
    • http://heatexchangersolution.com/upload_fck/file/2021-9-12/20210912070057719831.pdf
    • https://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/161410d7208d70---roruvuzolilozivipugu.pdf
    • http://kadh.kr/bobod/upload/file/94900298064.pdf
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161336afaee0ff---53470358970.pdf
    • https://classoft.ro/userfiles/file/83783688059.pdf
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/161410d72ca173---2214899345.pdf
    • http://euro-ex.com/images/blog/file/tukesuvedirelosozamegewi.pdf
    • http://redskap.ru/userfiles/file/82933287151.pdf
    • http://goforthegreengolfpools.com/userfiles/file/86353520594.pdf
    • https://alkalacarservice.com/public_html/userfiles/file/77012437586.pdf
    • 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_off0000e062.bin
2069f3e4f985ca85994fb51643b8dbdbaed4e5a86c0f34a2826884a2e298be5b
pdf-font-stream PDF embedded font (sfnt) at offset 0xE062 16404 bytes
font_01_sfnt_off00010abe.bin
9132bf6c9acd67e251a81a579f05c96d885e96e39e47ce082f8493e6dd278950
pdf-font-stream PDF embedded font (sfnt) at offset 0x10ABE 10180 bytes
font_02_sfnt_off00012199.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12199 16792 bytes