Malicious PDF — malware analysis report

Static analysis result for SHA-256 f921c91cad9b7c6d…

MALICIOUS

PDF

39.5 KB Created: 2020-07-12 15:10:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c817db6893a46ff0788373c8af6dbd0e SHA-1: a7c3de0496f64f45f5e74326bf51719ab16eb4b6 SHA-256: f921c91cad9b7c6d73f83932cf87cb162299f8e61f57d24554a13aac8f6a3c79
152 Risk Score

Malware Insights

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

The PDF was flagged by a critical heuristic for linking to known malicious redirector infrastructure and for containing a large link farm. The ML classifier also strongly indicated maliciousness. The embedded URLs, particularly the one pointing to ttraff.ru, are likely part of a campaign to lure users to malicious sites, potentially for phishing or malware distribution. The document body contains a mix of text and URLs, reinforcing the idea of a content-based 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.ru/wb?keyword=rural%20sociology%20pdf%20agrimoon
    • http://files.violinstringreview.com/uploads/1/3/1/4/131437147/31599a42625.pdf
    • http://files.soque.org/uploads/1/3/1/6/131607575/gukufoza-sezagobije.pdf
    • http://files.ollhschool.org/uploads/1/3/1/4/131453206/9196515.pdf
    • http://files.yackamoorundielandcaregroup.com/uploads/1/3/0/7/130738576/f55136849ebb37.pdf
    • http://files.beebefarm.info/uploads/1/3/0/7/130739910/9dd6ef8.pdf
    • http://files.squareonegoodsco.com/uploads/1/3/2/8/132815154/tasawaz.pdf
    • https://jutolaw.files.wordpress.com/2020/07/torukerigivewijofu.pdf
    • https://wisalamom.files.wordpress.com/2020/07/puziko.pdf
    • https://jexoxaluk.files.wordpress.com/2020/06/zoxerozajaxuwafosasokige.pdf
    • https://cdn.shopify.com/s/files/1/0432/9360/6046/files/jefalataxudalexosawig.pdf
    • https://cdn.shopify.com/s/files/1/0428/9613/0211/files/penirajod.pdf
    • https://cdn.shopify.com/s/files/1/0430/6737/5770/files/34991388852.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/nemubowakupupoda.pdf
    • https://cdn.shopify.com/s/files/1/0434/2808/5912/files/52204505632.pdf
    • https://cdn.shopify.com/s/files/1/0432/6470/4662/files/ferakozapitezederif.pdf
    • https://cdn.shopify.com/s/files/1/0430/3188/8021/files/zowula.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_off00005bc4.bin
9dfec1c6bf3639269677b675771f98547a5b8a2259371113a83d93841e3d3094
pdf-font-stream PDF embedded font (sfnt) at offset 0x5BC4 5268 bytes
font_01_sfnt_off00006d96.bin
fd67654432c9900590f368eccd97f33014aa71620c5a7f07b71fe15fdfe66711
pdf-font-stream PDF embedded font (sfnt) at offset 0x6D96 10456 bytes