Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4a31d98f2b451dc…

MALICIOUS

PDF

119.5 KB Created: 2021-08-18 11:58:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 0dc5cb17a44cacac527f02bead7d9d31 SHA-1: 434b4b64383075357c3e0515d194e27029a25577 SHA-256: f4a31d98f2b451dc16d598a627d3604285a9c60c2bc86a036a462ad72126ba48
156 Risk Score

Malware Insights

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

The sample was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to multiple compromised websites and disposable hosting domains, likely to distribute further malware. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic confirms the presence of numerous links pointing to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://vgi-vn.vn/app/webroot/img/files/mirawekujonewe.pdf In PDF document text
    • http://konditsionery-reutov.ru/upload_picture/file/72100294592.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608aae5f8aded---razokuwosumabip.pdfIn PDF document text
    • https://shreenathtechnologies.com/userfiles/file/26265025600.pdfIn PDF document text
    • http://hermandadperdon.es/userfiles/file/19575871024.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607e489eeea2c---8941439766.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16078fb457187a---bixorogonene.pdfIn PDF document text
    • https://airbays.com/userfiles/file/80963620796.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/1607f7321a0c49---8815897711.pdfIn PDF document text
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afa1af6a629---tipuxomumezanopupexifux.pdfIn PDF document text
    • http://altinay-law.com/images/file/sigorisarikubujuleja.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/7c002c6987a0c6ddd81e84895c74653b/bazixe.pdfIn PDF document text
    • https://tasivn.com/upload/ck/files/6710576708.pdfIn PDF document text
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dc0b66e527e---7367297999.pdfIn PDF document text
    • http://yameitecl.com/ckfinder/userfiles/files/20210726_045942.pdfIn PDF document text
    • https://resicolor.com/upload/files/sapewulejud.pdfIn PDF document text
    • https://majorsagilekvaros.hu/uploads/file/30345081168.pdfIn PDF document text
    • https://xn----7sbbjg7ctfs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/9e581f180a7debccf82d9bd08d072b6f/xivozubowa.pdfIn PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160715477ad59d---1636723799.pdfIn PDF document text
    • https://christembassybarking.org/wp-content/plugins/super-forms/uploads/php/files/d898fcbe903242cec0f4386aad7876ff/zuxiwefeg.pdfIn PDF document text
    • https://nazragame.com/calisma2/files/uploads/lojaruxazuwapuderoxu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=which+molecules+exhibits+hydrogen+bonding+when+dissolved+with+waterPDF 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_off0001646c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1646C 11416 bytes
SHA-256: 16c19a2cf5bc5df7a2031d63519a5c64a9ec502cdc408466ede6a1db59c7870f
font_01_sfnt_off00017f11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17F11 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00019723.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19723 20220 bytes
SHA-256: 50f562cddd01bdb1697f408ffed2e96d5723181dd8ff1c57847f5a987d717926