Malicious PDF — malware analysis report

Static analysis result for SHA-256 fd8fdd81f5ae4dee…

MALICIOUS

PDF

47.0 KB Created: 2020-08-31 21:07:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: cab97fa0a4f66f0b99feea42b6903b62 SHA-1: 6711e4b59eedb3a9b83cc5e8206ba9b29180df45 SHA-256: fd8fdd81f5ae4dee8c4de54528cd59a651ac1a376a709e967fd9a17e614eef6c
152 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for a malicious redirector link, pointing to 'https://ttraff.ru/pify?keyword=dividing+fractions+worksheet+6th+grade+with+answers'. This URL is presented within the document body, disguised as a link to a 'dividing fractions worksheet'. The PDF also exhibits characteristics of a link farm, with numerous embedded URLs. 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=dividing+fractions+worksheet+6th+grade+with+answers
    • https://static.usrfiles.com/ugd/34e21e_7657a92ece9e4f5e82ca98208ef10d2f.pdf
    • https://static.usrfiles.com/ugd/0bcf16_2e5cb602a9e748d2b295962da91a7593.pdf
    • https://static.usrfiles.com/ugd/b8c837_053808e8de0a4b62b6f65f7f8946bbac.pdf
    • https://static.usrfiles.com/ugd/0cd3a8_fcfd0e6b5afb47339d7d2a9bd7b6440f.pdf
    • https://cdn.shopify.com/s/files/1/0431/6371/3695/files/mozozakibarikak.pdf
    • https://cdn.shopify.com/s/files/1/0430/5253/1869/files/kidevuvunanidubo.pdf
    • https://cdn.shopify.com/s/files/1/0432/1656/8482/files/76483591463.pdf
    • https://cdn.shopify.com/s/files/1/0431/2514/5760/files/nixuwozikef.pdf
    • https://cdn.shopify.com/s/files/1/0433/7372/3800/files/fafutuzibojelibi.pdf
    • https://cdn.shopify.com/s/files/1/0438/6213/0853/files/game_of_thrones_show_bible.pdf
    • https://cdn.shopify.com/s/files/1/0437/0844/8919/files/rimazu.pdf
    • https://cdn.shopify.com/s/files/1/0433/1339/7924/files/18027290233.pdf
    • https://cdn.shopify.com/s/files/1/0429/3040/5535/files/33931747329.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/
    • https://static.usrfiles.com/ugd/34e21e_7657a92ece9e4f5e82ca98208ef10d2f.p

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000798e.bin
abd301784fd2032a258d12dbdf9e71da4aa71a1a4f5dac20964217c7476365d3
pdf-font-stream PDF embedded font (sfnt) at offset 0x798E 5620 bytes
font_01_sfnt_off00008ccc.bin
a12751507e5b769c01d1caffbb6212f7abec98fd49f769df25355edbbc434ee4
pdf-font-stream PDF embedded font (sfnt) at offset 0x8CCC 9980 bytes