Malicious PDF — malware analysis report

Static analysis result for SHA-256 fa4c0403bb0a8e2b…

MALICIOUS

PDF

45.9 KB Created: 2020-08-06 04:52:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 24dd6b23325580dde53f9dc178c6a2f7 SHA-1: fe83620118129b99dcd657527beb2e9ef08cb5cb SHA-256: fa4c0403bb0a8e2bebc8012aabe3c325efa1539469a8cb9b398fc0bd8797a29d
154 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to what appears to be a link farm designed to improve SEO rankings. One of the primary links redirects to a known malicious domain, ttraff.ru, suggesting a phishing or malware distribution attempt. The document body, though partially corrupted, contains text related to 'rational expressions pdf', likely a lure to attract users searching for educational materials. The ML classifier strongly flagged this PDF as malicious.

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=addition+and+subtraction+of+rational+expressions+pdf
    • http://files.gibtech.net/uploads/1/3/0/9/130969761/8a239732eebb718.pdf
    • http://files.rvtkd.com/uploads/1/3/2/3/132303351/jupulepazi.pdf
    • http://xubuk.southribble-greatwar.com/uploads/1/3/0/8/130874254/d4e9e3e25.pdf
    • https://cdn.shopify.com/s/files/1/0434/6799/7344/files/biltong_box_plans.pdf
    • https://cdn.shopify.com/s/files/1/0432/6427/8686/files/lowes_credit_card_services.pdf
    • https://cdn.shopify.com/s/files/1/0432/6660/5211/files/xomedutinolupefizif.pdf
    • https://cdn.shopify.com/s/files/1/0432/0401/8336/files/dunubutifofufulujere.pdf
    • https://cdn.shopify.com/s/files/1/0430/5797/1362/files/76323180957.pdf
    • https://cdn.shopify.com/s/files/1/0428/9003/5366/files/55998782568.pdf
    • https://cdn.shopify.com/s/files/1/0433/3237/0584/files/52360885263.pdf
    • https://cdn.shopify.com/s/files/1/0427/7361/0663/files/84210155802.pdf
    • https://cdn.shopify.com/s/files/1/0438/4381/3538/files/72043971966.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/mefopevepal.pdf
    • https://cdn.shopify.com/s/files/1/0429/9656/4131/files/pegedibi.pdf
    • https://cdn.shopify.com/s/files/1/0431/6083/0111/files/xuzajidunadubiwaxefiru.pdf
    • https://cdn.shopify.com/s/files/1/0436/4291/2926/files/dulujumomitabekobotera.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_off000070d7.bin
a3df73fa2063592a8a70d73b0946e9da9d3bb0df245aba15eef42380745f4845
pdf-font-stream PDF embedded font (sfnt) at offset 0x70D7 5348 bytes
font_01_sfnt_off00008318.bin
828a916fff96c331a14706ab2dde9d5eda97281d14cec255260c9d31458d6cf6
pdf-font-stream PDF embedded font (sfnt) at offset 0x8318 12288 bytes