Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c3bb6f5e51b2223…

MALICIOUS

PDF

84.4 KB Created: 2021-09-14 09:28:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3b2beed0b283a9709a557139a8ae7cb4 SHA-1: 55fee8848b13b62bb7a9f7cf31dfb21962614079 SHA-256: 9c3bb6f5e51b2223f1072c75fa1ebbe5604ffbd9ddede9a5e653412407dc5870
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier, indicating malicious intent. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or are part of a link farm on disposable hosting, suggesting a phishing or malware distribution scheme. The document body is heavily obfuscated and appears to be metadata from the wkhtmltopdf tool rather than user-readable content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://topclassgreenery.nl/images/file/38886952858.pdf
    • http://ckud.handysociality.com/upload/files/65398632539.pdf
    • http://plise.org/userfiles/file/52153043332.pdf
    • http://phuclocvienjsc.com/uploads/image/files/71557388618.pdf
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/48073b3a9b1966296d54bc83377ea8d7/xufebiwijudupopeso.pdf
    • https://history.tlshaa.org.tw/ckfinder/userfiles/files/fosomadagatilawakebimejap.pdf
    • http://bienbao.org/uploads/files/22126591583.pdf
    • http://hndgyl.com/v15/Upload/file/202196926393775.pdf
    • https://ceccarbotosani.ro/userfiles/file/97484132380.pdf
    • https://congtydaihai.com/upload/files/55073943328.pdf
    • http://thanhnienxp.com/vietkiendo/upload/file/1283909030.pdf
    • http://twsl.mingann.info/upload/ckfinder_temp/files/20210907111449.pdf
    • http://tko.wavedev.net/img/files/files/6741919921.pdf
    • http://naturestuff.nl/siteimages/file/75940696364.pdf
    • https://itscebu.com/upload/file/20210907090214.pdf
    • http://i-tos.com/userData/board/file/34098901887.pdf
    • https://fundacjaartfreeart.pl/userfiles/file/vutumagepinufoxak.pdf
    • https://rafaela-motores.com/userfiles/file/mevelogakapoboxuruwupe.pdf
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/b3404cd8a13493ec4530db942692bdce/31710368885.pdf
    • http://dedanskecasinoer.dk/userfiles/file/63119765810.pdf
    • https://steammining.com/userfiles/file/43485997268.pdf
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/1613558ddf0377---jeweresufoxo.pdf
    • http://brilspa.ro/userfiles/file///retuvakekizi.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=ullu+web+series+watch+online
    • 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_off0000e40b.bin
bbe6e04f457201dc12504baafd98317088b4a3792cc5003894a5bd27a34495db
pdf-font-stream PDF embedded font (sfnt) at offset 0xE40B 18168 bytes
font_01_sfnt_off00011354.bin
c2bdb0c1f4587a848010c7dc30fe3ba8ddf0bd71b4b3f323aa1e46930b21eff7
pdf-font-stream PDF embedded font (sfnt) at offset 0x11354 10660 bytes
font_02_sfnt_off00012bc4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12BC4 16792 bytes