Malicious PDF — malware analysis report

Static analysis result for SHA-256 41bbeb8ef35fbaea…

MALICIOUS

PDF

51.0 KB Created: 2020-08-13 23:09:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 22babf013db78140c97d1d52abfa2d33 SHA-1: e2341ac2d5b0a270bd0b4999552ff93972691550 SHA-256: 41bbeb8ef35fbaeabbe44ff88049f5b63e3d6b6bb7b26ef22343d54528e92f4e
154 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with one identified as a malicious redirector. The document body, though heavily obfuscated, contains text related to 'hard brain teasers and answers' and the malicious URL, suggesting a lure to trick users into clicking potentially harmful links. The ML classifier strongly indicated maliciousness.

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.ru/pify?keyword=hard+brain+teasers+and+answers
    • http://guteso.painandperformancesolutions.org/uploads/1/3/0/9/130969352/5994286.pdf
    • http://nufixojow.frederickjbrittain.com/uploads/1/3/1/3/131383483/0e440d41faec1.pdf
    • http://files.thenetworkedlibrarian.com/uploads/1/3/0/8/130874240/3460128.pdf
    • http://files.flourishinglifesociety.com/uploads/1/3/1/8/131856569/b67b1977.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/32177526878.pdf
    • https://cdn.shopify.com/s/files/1/0432/6732/6112/files/kodemozitix.pdf
    • https://cdn.shopify.com/s/files/1/0451/0928/0933/files/absite_review_fiser_download.pdf
    • https://cdn.shopify.com/s/files/1/0431/7144/6939/files/16509098552.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/66083684812.pdf
    • https://cdn.shopify.com/s/files/1/0435/8583/1070/files/foxepevuraguperinugena.pdf
    • https://cdn.shopify.com/s/files/1/0431/3051/9709/files/luvejenumibuwod.pdf
    • https://cdn.shopify.com/s/files/1/0438/6373/6485/files/alimentacion_sana_para_nios.pdf
    • https://cdn.shopify.com/s/files/1/0437/6661/2130/files/download_awe_inspiring_me.pdf
    • https://cdn.shopify.com/s/files/1/0428/9314/8313/files/zexegiluso.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_off00008a47.bin
16d58a956b588cf4bc9e0edc05a7c3d0eb0ae5e4bea253fc3257128bddeefb45
pdf-font-stream PDF embedded font (sfnt) at offset 0x8A47 4980 bytes
font_01_sfnt_off00009b52.bin
66c919f6dc1778d1afc09b1e3cfaa97eb151c3e431f794e3bf7f437fe72fdf26
pdf-font-stream PDF embedded font (sfnt) at offset 0x9B52 10404 bytes