Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5bbc77bc98cd3aa…

MALICIOUS

PDF

85.9 KB Created: 2021-09-18 06:04:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 584092df2dd1856873595d1acb96e794 SHA-1: 50ca9bffa21fc4821ff887f03276f076c5fee88d SHA-256: a5bbc77bc98cd3aa43544cf773024a5a1a82a00a6205ad2f747fef391e3592b6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs and is flagged as a link farm, with several pointing to compromised or disposable hosting. The presence of 'utm_term' parameters suggests a phishing or marketing lure. ClamAV detection and ML classification confirm its malicious nature, likely serving as a dropper or redirector to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://allytemp.ru/uplcv?utm_term=app+folder+in+android PDF link annotation
    • http://kstarsmall.net/userfiles/file///zukazazujipuzedodag.pdfIn PDF document text
    • http://thucphamchucnangmy.vn/uploads/files/57837869729.pdfIn PDF document text
    • http://bacvietexpress.com/upload/userfiles/files/69595577397.pdfIn PDF document text
    • http://dylogistics.com/userData/board/file/benunanurisawa.pdfIn PDF document text
    • https://alistairmills.com/ckfinder/userfiles/files/rubigafo.pdfIn PDF document text
    • http://czerwoneiczarne.pl/files/file/61475719502.pdfIn PDF document text
    • https://kalimati.in/userfiles/file/17855961152.pdfIn PDF document text
    • https://betsin.org/userfiles/files/tizepo.pdfIn PDF document text
    • http://zamgph.com/uploads/file/031411075231.pdfIn PDF document text
    • http://gensugroup.com/upload/files/tumezijedexisoja.pdfIn PDF document text
    • https://tahitotfalu.hu/ckfinder/userfiles/files/niziwuzowipufotixufonofa.pdfIn PDF document text
    • http://sangjeom.com/userfiles/file///vowuputerosapupezeve.pdfIn PDF document text
    • http://topup-fight.com/ckfinder/userfiles/files/46485507104.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/113c30c926de94d0b7498004fcf6499d/55224130027.pdfIn PDF document text
    • http://santabruna.cl/upload/file/fobibe.pdfIn PDF document text
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/c7de5bb0ec001fdaebed80f32c2a0475/77832755426.pdfIn PDF document text
    • http://burchiellati.com/file_fck/file/46372988413.pdfIn PDF document text
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/036330a880bebd69f3a0e876a7b26459/13072089368.pdfIn PDF document text
    • http://erh-hu.com/userfiles/file/80369333078.pdfIn PDF document text
    • https://digbijoynath.in/uploads/userfiles/files/166636578.pdfIn PDF document text
    • http://www.anglometais.com.br/adm/Editor/ckfinder/userfiles/files/sagisasid.pdfIn PDF document text
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/16140af118260d---wopezomumuvifikejemix.pdfIn PDF document text
    • http://ubytovna-krumlov.cz/userfiles/file/38131124551.pdfIn PDF document text
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143163711462---99742638648.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_off0000ecfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECFE 10204 bytes
SHA-256: 645c800639a2ee4b2cf2e4b45305e9cdf9b6880e6538e21dc2b0a52c034c190d
font_01_sfnt_off000103e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103E0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011bf2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BF2 17384 bytes
SHA-256: ab7ec9b83059fdfb7e72c15ebd4011482bd7fae5aeb6a5b4fd2c31aeacdb47cb