Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f1eab8a35b0ad16…

MALICIOUS

PDF

40.5 KB Created: 2020-08-05 01:44:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d76415b501b253cf101775f640ec37a8 SHA-1: 634d1556f043ed77552dc6b3e9bb6caad4a02b6c SHA-256: 4f1eab8a35b0ad169d0d92683fcf8ff5ec89207562e5fedb3fcba9730f9b7540
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains embedded links that lead to a malicious redirector, disguised as a drawing tutorial. The heuristic PDF_MALICIOUS_REDIRECTOR_LINK and PDF_SEO_LINK_FARM indicate that the document is part of a link farm designed to redirect users to malicious sites. The ML classifier also strongly flagged this PDF as malicious. No scripts were extracted, but the embedded URLs are the primary mechanism for the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://ttraff.com/pify?keyword=color+pencil+drawing+for+beginners+pdf
    • http://files.artbyronda.com/uploads/1/3/1/4/131408142/8956724545572f4.pdf
    • http://files.creativeenergyart.com/uploads/1/3/2/8/132815882/9558734.pdf
    • http://files.veinclinicmb.com/uploads/1/3/1/8/131857679/xekabafi_kamotipevilum.pdf
    • http://files.creativehecovid.org/uploads/1/3/0/7/130776220/f08f1ea7e4a.pdf
    • http://kozepuv.derekleebarton.com/uploads/1/3/1/6/131606407/af6828b7621d7.pdf
    • https://cdn.shopify.com/s/files/1/0431/3317/3927/files/abrsm_grade_4_piano_2020_pieces.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/kiwovanigefuminif.pdf
    • https://cdn.shopify.com/s/files/1/0435/2131/0875/files/21035766198.pdf
    • https://cdn.shopify.com/s/files/1/0435/4909/8148/files/begepawisegeletim.pdf
    • https://cdn.shopify.com/s/files/1/0430/9578/5621/files/47082939988.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/redukenedobitaguwowok.pdf
    • https://cdn.shopify.com/s/files/1/0433/2398/1979/files/ponejeku.pdf
    • https://cdn.shopify.com/s/files/1/0432/3291/9720/files/guveworibiwopafefuvan.pdf
    • https://cdn.shopify.com/s/files/1/0431/6237/0210/files/core_strengthening_exercises.pdf
    • https://cdn.shopify.com/s/files/1/0428/7938/5766/files/70593746559.pdf
    • https://cdn.shopify.com/s/files/1/0432/6113/2968/files/95132596228.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/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006055.bin
be39f93b73012324baac046d8401f4f8f90664e3b780c4f2218fdcac52a5aa3a
pdf-font-stream PDF embedded font (sfnt) at offset 0x6055 5460 bytes
font_01_sfnt_off00007303.bin
79be29f036f3c79def7d407e91c57a21662613e409bf9aa3e2a45df8a8268017
pdf-font-stream PDF embedded font (sfnt) at offset 0x7303 9992 bytes