Malicious PDF — malware analysis report

Static analysis result for SHA-256 887c84e55d41453f…

MALICIOUS

PDF

76.6 KB Created: 2021-09-07 14:35:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 60adfac4faecd665af77cb8cfcd4efbc SHA-1: d1e29211847dd69a025b42187aa7482414f7cabf SHA-256: 887c84e55d41453fe19fe53ff9b2d015a956c64b615108394505109f510478aa
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external URIs and link farm patterns, indicating an attempt to redirect users to potentially harmful websites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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://krisoc.ru/uplcv?utm_term=mellerware+bread+maker+recipe+book+pdf PDF link annotation
    • http://puntolinea.org/userfiles/files/23909411105.pdfIn PDF document text
    • https://ijp2.com/contents//files/84026978709.pdfIn PDF document text
    • https://irrisyst.eu/files/file/96029382362.pdfIn PDF document text
    • https://agrachoff.ru/wp-content/plugins/super-forms/uploads/php/files/fe07210e1cd7582b1645286de480cff4/20972401446.pdfIn PDF document text
    • http://smartwealthhk.com/userfiles/legom.pdfIn PDF document text
    • http://wjvanderheidedienstverlening.nl/uploads/file/fasibabodakuwiserolula.pdfIn PDF document text
    • https://daotaolaixesontay.com/uploads/file/vakovulesisirunabodaw.pdfIn PDF document text
    • http://petraifevronii.ru/ckfinder/userfiles/files/62129172627.pdfIn PDF document text
    • https://33mobility.net/uploads/files/fudigumofejugo.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160b60d48168bf---poboluzijigabudo.pdfIn PDF document text
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16078204b907cf---tibejopixivuwawakeniba.pdfIn PDF document text
    • https://farstaslottsvik.nu/anvandarbilder/153/files/27223687364.pdfIn PDF document text
    • https://piataafacerilor.ro/app/webroot/files/userfiles/files/netezusobazadupeberobipew.pdfIn PDF document text
    • http://cancunday.com/travela/img/files/xanifabimawisaxidav.pdfIn PDF document text
    • http://chetaomaynganhnhua.com/uploads/files/vawofubobupanage.pdfIn PDF document text
    • https://tonitomov.com/picture/file/15813789030.pdfIn PDF document text
    • http://dzstock.com/Upfiles/file/firosa.pdfIn PDF document text
    • http://www.juniorcollege.cl/ckfinder/userfiles/files/wawenapozovasuvidari.pdfIn PDF document text
    • https://dewalt-naradi.cz/media/upload/editor/file/38786905565.pdfIn PDF document text
    • https://kiptep.ru/file/89740591252.pdfIn PDF document text
    • https://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/533ba2288305494ada30f2168133f055/didirudizubun.pdfIn PDF document text
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/i4cutub3nja0htbri0cn6veqs5/kijiwutodarejekubozo.pdfIn PDF document text
    • http://kino-profi.com/wp-content/plugins/super-forms/uploads/php/files/1ff15f1a65169885a38f023e59ee26ad/kebodaxiwarajuvakaji.pdfIn PDF document text
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c313825f53---90000441431.pdfIn PDF document text
    • https://clearpatth.com/userfiles/file/fujokadejopo.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_off0000c560.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC560 17620 bytes
SHA-256: b273d1757297905579eb839ba4d3d316fc6c3ce7ab9594077cfd2f69994dde1f
font_01_sfnt_off0000f2af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2AF 10720 bytes
SHA-256: ff5fcb30cc11dee5628c3b7df08da33a47201a0cd55449dc7e6fb7c88f8e75da
font_02_sfnt_off00010b1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B1D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1