Malicious PDF — malware analysis report

Static analysis result for SHA-256 519abef5fb4b079f…

MALICIOUS

PDF

79.6 KB Created: 2021-05-19 23:10:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 789c31397c23043039ce911b4b1b8d16 SHA-1: a347f5aaab8c82002bc5ca0c78b8c0e20f1d3318 SHA-256: 519abef5fb4b079f9e65ba366ec104847998170157f6fe9b08ec4640d4ffec40
216 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was flagged as malicious by ClamAV and an ML classifier, indicating a phishing and trojan threat. The document's content, though heavily obfuscated, appears to be a lure for downloading software, combined with a critical heuristic firing for 'Recovery secret / private key request'. This suggests an attempt to trick users into providing sensitive information under the guise of a software download. The presence of external URIs further supports the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • 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.
  • Recovery secret / private key request critical SE_SECRET_RECOVERY_LURE
    Document requests recovery phrases, private keys, backup codes, or saved passwords. Requests for these secrets in a document are high-risk.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://xezojetit.ru/strik?utm_term=chessmaster+grandmaster+edition+download
    • https://cdn-cms.f-static.net/uploads/4365545/normal_6040f268f1c12.pdf
    • https://cdn-cms.f-static.net/uploads/4472760/normal_60315554efe20.pdf
    • https://cdn-cms.f-static.net/uploads/4382430/normal_602002463580f.pdf
    • https://cdn-cms.f-static.net/uploads/4402712/normal_601b2915cb267.pdf
    • https://tabivivefevevu.weebly.com/uploads/1/3/4/8/134889686/2850644.pdf
    • https://cdn-cms.f-static.net/uploads/4495846/normal_602c60af4397b.pdf
    • https://takadoturig.weebly.com/uploads/1/3/4/1/134108809/884116e53b015.pdf
    • https://cdn-cms.f-static.net/uploads/4481852/normal_6021faf146002.pdf
    • https://cdn-cms.f-static.net/uploads/4379606/normal_60571c95cc4a9.pdf
    • https://zadivodewereb.weebly.com/uploads/1/3/2/6/132683121/639281.pdf
    • https://static.s123-cdn-static.com/uploads/4379485/normal_5fddfc400221b.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/013954eb-6684-41c4-93d2-29e52835aee9/70029185129.pdf
    • https://s3.amazonaws.com/dowadotiju/15042261260.pdf
    • https://s3.amazonaws.com/jodabiladezot/lukumezewemalusosim.pdf
    • https://s3.amazonaws.com/polojuliragam/bard_ffxiv_guide_shadowbringers.pdf
    • https://uploads.strikinglycdn.com/files/f648487f-3bcc-4bc6-b8f8-8910fda9e773/rovukisabomezesoxo.pdf
    • https://uploads.strikinglycdn.com/files/651eddc6-aa62-445d-b1c6-79a23277103b/best_home_printers_2020_cnet.pdf
    • https://uploads.strikinglycdn.com/files/8703e263-7b6e-4672-a66e-b7ca6743f690/acurite_thermometer_replacement_parts.pdf
    • https://uploads.strikinglycdn.com/files/d6c96c88-0eba-4710-b164-687653774402/3d_animation_software_for_ipad.pdf
    • https://s3.amazonaws.com/nupotukig/10920101470.pdf
    • https://s3.amazonaws.com/tiniruru/self-reliance_examples_in_school.pdf
    • 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_off0000f731.bin
9b3974928f895496962733cc514427f3c0aff8fb94e84df3d0c448a27552f670
pdf-font-stream PDF embedded font (sfnt) at offset 0xF731 5236 bytes
font_01_sfnt_off000108da.bin
1a916b67dd773f81b8f8a91abab0fe69a519991e126ca004c7046c4a54ded586
pdf-font-stream PDF embedded font (sfnt) at offset 0x108DA 11680 bytes