Malicious PDF — malware analysis report

Static analysis result for SHA-256 838c5b278d02895a…

MALICIOUS

PDF

77.0 KB Created: 2021-03-24 03:52:10 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f2a9b5668ac6caa90d5d0ea6b39177ea SHA-1: a4a8879a1dc1ff9f9f5cae8d3abfb6dbc4f39ee8 SHA-256: 838c5b278d02895ae1a14a72a6802afc8934826fdf9cc684a8b0e38118391beb
194 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

The PDF contains a large number of external links, many hosted on disposable domains, suggesting a link farm designed to redirect users to malicious sites. The 'SE_INVOICE_LURE' heuristic indicates the document's content is intended to deceive users into clicking these links. ClamAV detection and ML classification confirm the malicious nature of the PDF, likely serving as a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 7

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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://vilenefex.ru/123?utm_term=abridged+balance+sheet+means
    • https://tozabofosizo.weebly.com/uploads/1/3/5/3/135340530/4022339.pdf
    • http://rixorevu.getenjoyment.net/payroll_management_system_documentation.pdf
    • http://cabinetshq.xyz/why_is_my_whirlpool_microwave_not_heatingttckd.pdf
    • https://vezitiratad.weebly.com/uploads/1/3/1/8/131856143/xumemov-kizadolezuf.pdf
    • http://winoraama.website/define_survival_of_the_fittest_synonymg07l5.pdf
    • http://jasazotinalol.mygamesonline.org/errorcode-4461_sqlstate42815_date.pdf
    • https://cdn.sqhk.co/wisulekekij/9pUghje/cricket_live_match_2020.pdf
    • http://chelamela.org/corningware_percolator_how_to_use7e7ou.pdf
    • https://xevumijujivo.weebly.com/uploads/1/3/1/3/131383583/3904356.pdf
    • https://cdn.sqhk.co/xibetevoxaj/gieihgc/pixel_band_14.pdf
    • http://bonboxstudio.com/thermal_power_plant_commissioning_procedurexeeng.pdf
    • https://cdn.sqhk.co/zizenozi/jgBXSp1/meme_maker_free_download_for_pc.pdf
    • http://copyrightreports.com/intex_pool_sand_filter_setup_videocczbz.pdf
    • http://zinefikitozozeg.sportsontheweb.net/sulananan.pdf
    • https://wojopegoguw.weebly.com/uploads/1/3/4/6/134690206/971f38f0c.pdf
    • http://dajexori.mypressonline.com/33784632223.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://e4fb9bf1-a3d6-4767-9bf2-2a1021e5dc09.filesusr.com/ugd/53cfc7_852887f5c8bb4603a8906cf3751ac0bc.pdf?index=true
    • http://vezapuro.rf.gd/kumon_answer_book_level_d2.pdf
    • http://zikimopotefeva.epizy.com/sar_suspicious_activity_report_sample.pdf
    • http://xekabotiwuker.atwebpages.com/49249574688.pdf
    • http://pititonekeget.epizy.com/18668987329.pdf
    • http://rufopanapoxo.rf.gd/ccna_spanning_tree_protocol.pdf
    • http://redilupabisaxo.rf.gd/2601450400.pdf
    • https://2ea9429b-0332-4ee6-bb75-ab9535b56c99.filesusr.com/ugd/e2f7e1_dd93be3b86314e45be80928821b8bcc2.pdf?index=true
    • https://989244f3-426d-4557-b4f1-0018dac9047c.filesusr.com/ugd/57c819_694d2ec0823c497ebb0f11d19b55990d.pdf?index=true
    • https://4ad55601-b8ab-4ae0-bc0e-e90069072326.filesusr.com/ugd/3aca14_7768956157ee43a7a20011a140b849e5.pdf?index=true
    • https://e05653fc-386e-4c8b-889d-738aee72c63e.filesusr.com/ugd/62421a_d495fb91e1904da8bdb7e0d0c795b140.pdf?index=true
    • 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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000edfa.bin
a3cb5b96fb2f240bd4c851a02ff7cf93cbf07f050885f46d752cc28c6f66e4b3
pdf-font-stream PDF embedded font (sfnt) at offset 0xEDFA 5484 bytes
font_01_sfnt_off0001006e.bin
65dba5f9cbed807cc5eb0aecaf8186faf7d3b216651c0cc16f9ab2aa1c0d0f60
pdf-font-stream PDF embedded font (sfnt) at offset 0x1006E 10652 bytes