Malicious PDF — malware analysis report

Static analysis result for SHA-256 725beca548bfd885…

MALICIOUS

PDF

41.0 KB Created: 2020-08-23 07:24:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 84f4c8bb9d27b886b7ed55d00bc4ec9d SHA-1: 80f4db78545f1d0a2b064e02865faae4b6a02c1a SHA-256: 725beca548bfd885b40f07efc7b5b08aa4c81a750bd8fdc3e3b46564e44b5769
154 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to benign Shopify domains, but one critical link redirects to known malicious infrastructure at `ttraff.cc`. This suggests a link farm or SEO poisoning tactic to distribute malicious content. The ML classifier also strongly flagged this PDF as malicious. The document body, though heavily corrupted, contains the text 'Performance appraisal review letter' and the malicious URL, reinforcing the lure.

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=performance+appraisal+review+letter
    • http://files.wildmillers.com/uploads/1/3/1/4/131407406/3238706.pdf
    • http://labaforif.albedooshrine.org/uploads/1/3/0/8/130874493/4270492.pdf
    • http://files.ncelementary.com/uploads/1/3/1/4/131453267/nevosimujutob.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://cdn.shopify.com/s/files/1/0433/5042/5753/files/cornerstone_chords_g.pdf
    • https://cdn.shopify.com/s/files/1/0439/0833/3736/files/advanced_cardiac_life_support_acls_provider_handbook.pdf
    • https://cdn.shopify.com/s/files/1/0440/5451/1766/files/turovapisulasek.pdf
    • https://cdn.shopify.com/s/files/1/0440/0028/0726/files/pobamepopurid.pdf
    • https://cdn.shopify.com/s/files/1/0450/6628/9302/files/93525119586.pdf
    • https://cdn.shopify.com/s/files/1/0447/9015/3365/files/bobisixedalipekuz.pdf
    • https://cdn.shopify.com/s/files/1/0430/8425/1285/files/62272511579.pdf
    • https://cdn.shopify.com/s/files/1/0431/7455/9893/files/83445290275.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_off000061f7.bin
e582f5014d5772550d99c133d4a4c386b217e3723c89c09821022b06e2b8a88e
pdf-font-stream PDF embedded font (sfnt) at offset 0x61F7 5316 bytes
font_01_sfnt_off000073ff.bin
fb1c95958215cfc84950e3e86581bf725265970a70d395b2571d8ea7653ae771
pdf-font-stream PDF embedded font (sfnt) at offset 0x73FF 10364 bytes