Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc8eaf21d2f6db70…

MALICIOUS

PDF

87.4 KB Created: 2021-09-15 22:17:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 34175b88b7eda5e02d1ec90de96d486f SHA-1: 8c24fc0b1f2b604c3d16c74dfb440bc50e837621 SHA-256: bc8eaf21d2f6db708e892468ec4e08be90c3b05cb66e41c37b983595b862785d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm directing to numerous external URLs, with several hosted on compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. No scripts were extracted, but the structure and URL targets suggest an attempt to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://cualuoihoanmy.com/uploads/userfiles/file/1246351109.pdf In PDF document text
    • https://777mto.com/contents/files/gaguxaduzoxilimazenawi.pdfIn PDF document text
    • http://vetranhtuong.info/luutru/files/nijaboniwumuxuvidob.pdfIn PDF document text
    • http://datavincity.com/uploads/ckfinder/files/xivurekasakuru.pdfIn PDF document text
    • http://xn----8sbemnkjd7bfu.xn--p1ai/design/img/upload/file/guvusituxex.pdfIn PDF document text
    • https://rwd.webseo.tw/upload/files/26779153629.pdfIn PDF document text
    • http://a2kat.ru/userfiles/file/muwefa.pdfIn PDF document text
    • http://archi-m.ru/userfiles/file/vefeduzikixod.pdfIn PDF document text
    • https://fluffy-chins.com/images/file/2062826569.pdfIn PDF document text
    • http://vijyaiprismcrm.com/userfiles/files/zibidufidipos.pdfIn PDF document text
    • http://starwindows.ie/ckfinder/userfiles/files/36694373178.pdfIn PDF document text
    • http://robotsuk.com/luckingbros.co.uk/userfiles/files/83118544968.pdfIn PDF document text
    • https://srinivasagroup.com/ci/userfiles/files/dodanifuzerowajelezafaso.pdfIn PDF document text
    • http://rfinshaat.az/userfiles/file/55268000500.pdfIn PDF document text
    • http://tsuiteru66.com/userfiles/file/lejikekozijifudovape.pdfIn PDF document text
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e962993387---buwunamifo.pdfIn PDF document text
    • https://propbrains.com/wp-content/plugins/super-forms/uploads/php/files/2f186bf70a8475dd379bfed8c6c2d81d/pixesejolaxawupixevup.pdfIn PDF document text
    • http://shendaoguoji.com/data/attachment/file/7893827137.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/kf9kp6advt1kpkrn8mg8ns1pir/koluledavuruk.pdfIn PDF document text
    • http://ahdjcm.com/upload/files/bowoporizovetuxudenexu.pdfIn PDF document text
    • https://amrapalispot.com/userfiles/file/91994399191.pdfIn PDF document text
    • http://itkaufmann.com/images/fckimages/file/ledumorukenazogokawabel.pdfIn PDF document text
    • https://pastravariaizvoarelebratiei.ro/images/file/44179654723.pdfIn PDF document text
    • https://maffart-guy.com/userfiles/file/sagerowaga.pdfIn PDF document text
    • http://bakefruit.com/uploads/files/202109102207589697.pdfIn PDF document text
    • https://www.corpeverest.com/ckfinder/userfiles/files/76773264662.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=clean+up+space+androidPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f0a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0A3 18356 bytes
SHA-256: c7e77592fcd2c21723da4c08645f33f5af2b14cea1b81f5a7c9430ecd4e6f4a6
font_01_sfnt_off00011fcc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FCC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000137e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137E3 10540 bytes
SHA-256: 85ffa1cbfe4f96361b5fcdd4644dfaae86e448d85c725c2505dced37ec63c63e