Malicious PDF — malware analysis report

Static analysis result for SHA-256 1511f80e1e80cfe3…

MALICIOUS

PDF

74.9 KB Created: 2021-09-24 20:13:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: eddb90cc954e42dc619ad62d0db519dc SHA-1: d36808fa3375e5542c087c1ece046f56fd47a93e SHA-256: 1511f80e1e80cfe33779ff65aebcc66d6a796c23a58531e59131e2793c9bae86
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS platforms. While no scripts were explicitly extracted, the nature of PDF link farms often involves JavaScript to facilitate redirection, hence the inclusion of T1059.007.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 http://autosklo.sk/pictures/file/petoxozebugolunogubuvajub.pdf
    • http://espokebar.com/uploads/files/takiwo.pdf
    • https://sklepbonus.pl/userfiles/file/95488701979.pdf
    • http://top-caster.com/userfiles/file/putunalozagimatar.pdf
    • https://sipsib.ru/wp-content/plugins/super-forms/uploads/php/files/c8b250a8f3f05b6d0d6270c40b622921/38925343374.pdf
    • https://natyabio.com/uploadfiles/tejuzo.pdf
    • http://kutyasturak.hu/images/files/goxonofukalowiwadizowe.pdf
    • http://rivebistro.net/ckfinder/userfiles/files/ziziropagiwakopewet.pdf
    • https://snf.styleguides.ch/userfiles/files/vavupagalapokenaja.pdf
    • https://ctners.com/ckfinder/userfiles/files/jegimememategi.pdf
    • http://pharmabiosolutions.com/filespath/files/20210919203648.pdf
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/2341710bd98e5714c0386ec770878a86/rudolefajugan.pdf
    • http://bbhshipyard.com/userfiles/file/larulanezug.pdf
    • http://cableesmaltado.com/d/files/99179462765.pdf
    • https://la-klamm.org/Files/files/dofob.pdf
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/a2dfdd728586d627a5dd77ede2fd6976/10567148436.pdf
    • https://urbanshapes.in/userfiles/file/66693978681.pdf
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/161338c724a0cc---99333980376.pdf
    • http://huynhgiabaohotel.com/uploads/FCK/file/99645324918.pdf
    • http://kcpsystem.com/userData/board/file/29158283916.pdf
    • https://kozlovka.mebel18.com/uploads/files/73673168198.pdf
    • http://cuacuonnhaxuongbinhduong.com/upload/files/3034204893.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=nonton+film+jack+reacher+2016
    • 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_off0000bcf7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBCF7 16792 bytes
font_01_sfnt_off0000d509.bin
4febacdefea78e3d639d07f509938f386665440b2279cf56ca60426955936af6
pdf-font-stream PDF embedded font (sfnt) at offset 0xD509 17828 bytes
font_02_sfnt_off0001025f.bin
eb19df32b4f76f2641d9627bc7c8351def79f482a2d6be86ab7d8bdce26be995
pdf-font-stream PDF embedded font (sfnt) at offset 0x1025F 11092 bytes