Malicious PDF — malware analysis report

Static analysis result for SHA-256 da2cf6361fee62bb…

MALICIOUS

PDF

37.8 KB Created: 2020-08-01 17:06:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f6271ac4b42a41b71a7da09885dd3258 SHA-1: 8060c00e240ec5bc8864bb1b92597df798bccdd3 SHA-256: da2cf6361fee62bbb582300b3b50a96f011745d3c67b1a3ef56d8d2d7a0407fa
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged as malicious by an ML classifier and contains a significant number of embedded links to external PDF files, constituting a link farm. One of these links points to a known malicious redirector, 'ttraff.cc', which is a strong indicator of malicious intent. The document body is heavily obfuscated and contains metadata suggesting it was generated by wkhtmltopdf, but the primary malicious activity appears to be the distribution of links.

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.cc/pify?keyword=vertical+line+css
    • http://files.hnartworks.com/uploads/1/3/1/8/131856353/dasubu.pdf
    • http://files.girlwithmanyjobs.com/uploads/1/3/1/0/131070030/vojodaxowisavenabek.pdf
    • http://files.abivaonlineresources.com/uploads/1/3/1/4/131453636/7e05af.pdf
    • http://files.orderibc.com/uploads/1/3/1/8/131871786/a70443bf1288b.pdf
    • https://cdn.shopify.com/s/files/1/0433/0127/3750/files/86648338429.pdf
    • https://cdn.shopify.com/s/files/1/0430/5806/9655/files/dosozegulosofelepubu.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/88075317933.pdf
    • https://cdn.shopify.com/s/files/1/0428/0313/4627/files/9895274684.pdf
    • https://cdn.shopify.com/s/files/1/0434/8638/0189/files/80917204788.pdf
    • https://cdn.shopify.com/s/files/1/0437/8984/4631/files/playboy_2015_collectors_edition.pdf
    • https://cdn.shopify.com/s/files/1/0430/7560/0535/files/vataradigikijidosafevixat.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/91428743782.pdf
    • https://cdn.shopify.com/s/files/1/0429/1218/6531/files/11245453713.pdf
    • https://cdn.shopify.com/s/files/1/0428/2603/9463/files/vufigabedof.pdf
    • https://cdn.shopify.com/s/files/1/0428/6483/6764/files/vuvuwasaxi.pdf
    • https://cdn.shopify.com/s/files/1/0431/8868/2915/files/20471596695.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/wekisod.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_off000055f3.bin
c9b55cf5487e64fce5aeded30997813fd4f713384b9480b399bbfd234510f1d9
pdf-font-stream PDF embedded font (sfnt) at offset 0x55F3 4756 bytes
font_01_sfnt_off0000662d.bin
bc9fadf50c300cad7e488d3915c17449c076b33c25770f876407912398aebf24
pdf-font-stream PDF embedded font (sfnt) at offset 0x662D 10720 bytes