Malicious PDF — malware analysis report

Static analysis result for SHA-256 22759e8ca73af228…

MALICIOUS

PDF

37.3 KB Created: 2020-08-28 11:20:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: caa41f01facfed40801d07ad7a922e3a SHA-1: 7bc5898675a7d7e9e3ce7b281f6d4026c7594bb7 SHA-256: 22759e8ca73af228498c1e0fc85d1ab96e34325fcc579a4eb646438240b2a1f9
152 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to a link farm hosted on ttraff.ru, which is flagged as a malicious redirector. The document body, though heavily garbled, contains references to academic-sounding titles and the wkhtmltopdf application, suggesting a lure to trick users into clicking malicious links disguised as legitimate content. The ML classifier also strongly indicated maliciousness.

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=algorithmen+und+datenstrukturen+f%25C3%25BCr+dummies+pdf
    • http://files.rocksfestivals.com/uploads/1/3/0/7/130775520/3467361.pdf
    • http://files.leoclubofjuhu.com/uploads/1/3/1/6/131606393/2758751.pdf
    • http://files.osukappaphilambda.org/uploads/1/3/1/4/131406453/zadituvedexigezopa.pdf
    • https://cdn.shopify.com/s/files/1/0434/1858/3192/files/56023115526.pdf
    • https://cdn.shopify.com/s/files/1/0434/6901/3144/files/17354503756.pdf
    • https://cdn.shopify.com/s/files/1/0432/7689/4372/files/pupupivatonidi.pdf
    • https://cdn.shopify.com/s/files/1/0434/4630/4933/files/gixiwunobulitaduzasegaked.pdf
    • https://cdn.shopify.com/s/files/1/0454/3338/9214/files/presentation_skills_tips.pdf
    • https://cdn.shopify.com/s/files/1/0433/3702/3656/files/willingness_to_pay.pdf
    • https://cdn.shopify.com/s/files/1/0437/6051/7274/files/70323679823.pdf
    • https://cdn.shopify.com/s/files/1/0434/5544/7202/files/downloadable_printable_calligraphy_practice_sheets.pdf
    • https://cdn.shopify.com/s/files/1/0434/2756/1621/files/bapivejuvofel.pdf
    • https://cdn.shopify.com/s/files/1/0434/4568/2328/files/48247107575.pdf
    • https://cdn.shopify.com/s/files/1/0438/0403/3181/files/sophos_endpoint_protection_standard_installation_guide.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_off00004f98.bin
32de0ba08e42e9cf24d99366160148fc84fa4014fecd315a94dfe78684a23830
pdf-font-stream PDF embedded font (sfnt) at offset 0x4F98 5628 bytes
font_01_sfnt_off00006260.bin
e082bab1489ee3abd0d8d3a277ee471752176f80113f8dc98d2034ca3bfbb930
pdf-font-stream PDF embedded font (sfnt) at offset 0x6260 10896 bytes