Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8990f0a835c41ee…

MALICIOUS

PDF

70.5 KB Created: 2021-09-11 18:58:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 02cb0ffb44337853d26e69c9599d3616 SHA-1: e73d0ce12479f2957b740d6c1196aac9580ad9c3 SHA-256: f8990f0a835c41ee4774d0e36c5e6186cfdfef578fbbb8900ff3182177e249ad
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, presenting numerous URLs that redirect to other PDF files. The presence of multiple external URIs and link farm characteristics suggests a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://pixomot.ru/uplcv?utm_term=how+to+root+oppo+a31 PDF link annotation
    • http://thepnguyentran.com/media/ftp/file/32354267505.pdfIn PDF document text
    • https://maconlux.lu/userfiles/files/fixulilizubolifilonam.pdfIn PDF document text
    • http://www.maderas-navarro.com/ckfinder/userfiles/files/97151192956.pdfIn PDF document text
    • http://mispuntossaga.com/campannas/file/fupase.pdfIn PDF document text
    • http://studiogallerani.it/userfiles/files/xapoxabakafujoxigaw.pdfIn PDF document text
    • https://ghadir-eng.com/userfiles/files/zisom.pdfIn PDF document text
    • http://bibrka-school.org.ua/ckfinder/userfiles/files/51523989096.pdfIn PDF document text
    • http://clean-ecology.com/Upload/files/3315509078.pdfIn PDF document text
    • http://doktor-okonski.pl/uploadimg/file/nesabonan.pdfIn PDF document text
    • http://residenceraffaellotorino.com/userfiles/files/11800896024.pdfIn PDF document text
    • https://afra24.com/basefile/afra24/files/fuvoxanadodivime.pdfIn PDF document text
    • https://sonntag-immobilien.lu/userfiles/files/59227935208.pdfIn PDF document text
    • https://omnistopbollards.com/application/third_party/ckfinder/userfiles/files/57074442668.pdfIn PDF document text
    • https://sherwoodchamber.org/ckfinder/userfiles/files/91720126483.pdfIn PDF document text
    • https://zippy-inc.com/app/webroot/userfiles/files/kamilibib.pdfIn PDF document text
    • http://ain.proximeo.com/ckfinder/userfiles/files/60755722781.pdfIn PDF document text
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130a62158994---zupalakedunezon.pdfIn PDF document text
    • http://nagymester.com/userfiles/file/pafinonedunodevanoxe.pdfIn PDF document text
    • http://bainihu.com/upfiles/editor/files/47638384776.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/16139993d7db12---bevaw.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/77159318306.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/c28474a2323c2b6b20652ff9797a3a9e/lujezemazubedax.pdfIn PDF document text
    • 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_off0000b361.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB361 10004 bytes
SHA-256: 93c939332d0342585303312cdca386e8864a97a1ef07993cd66b53ff5015e9a2
font_01_sfnt_off0000c9bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9BB 16724 bytes
SHA-256: 4369b437adb1779a1bd84241a2e1e0f686c308529700db205ad7a4dc3f8661f7
font_02_sfnt_off0000f47c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF47C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1