Malicious PDF — malware analysis report

Static analysis result for SHA-256 81b1dfe8574ecb35…

MALICIOUS

PDF

41.6 KB Created: 2020-08-31 02:39:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: fd0f1f3d31ccb09dffba29bf4cb5ec5c SHA-1: e0a1da946b8a705291697f73875906464962da7f SHA-256: 81b1dfe8574ecb35b19551b5169c315c2efe441fe6b9753caaa89b01c0e250c3
152 Risk Score

Malware Insights

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

The PDF document was flagged as malicious by an ML classifier and contains a critical heuristic indicating it links to known malicious redirector infrastructure. It also exhibits characteristics of a PDF link farm, with numerous embedded URLs pointing to external resources. The primary malicious URL identified is 'https://ttraff.ru/wix?keyword=ohm+walsh+review', which is likely used to lure victims into a phishing or malware distribution scheme. The document body contains obfuscated text and the malicious URL.

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/wix?keyword=ohm+walsh+review
    • https://cdn.shopify
    • https://cdn.shopify.com/s/files/1/0428/9232/9116/files/4537692083.pdf
    • https://cdn.shopify.com/s/files/1/0431/6971/0242/files/taxefatanorob.pdf
    • https://cdn.shopify.com/s/files/1/0435/2727/4645/files/xoxujupebojinepumari.pdf
    • https://cdn.shopify.com/s/files/1/0436/7224/0293/files/fajare.pdf
    • https://cdn.shopify.com/s/files/1/0437/1028/3931/files/jetomejazi.pdf
    • https://cdn.shopify.com/s/files/1/0429/9735/0554/files/aparato_digestivo_para_colorear.pdf
    • https://cdn.shopify.com/s/files/1/0461/7099/6889/files/chess_for_pc_filehippo.pdf
    • https://cdn.shopify.com/s/files/1/0431/5411/2672/files/13271853636.pdf
    • https://cdn.shopify.com/s/files/1/0434/7605/8274/files/36603773668.pdf
    • https://static.usrfiles.com/ugd/2b25b5_93e522fa3d364cfd9519305125079ae6.pdf
    • https://static.usrfiles.com/ugd/b52961_21b7a28f68384144bee92258dfb658fb.pdf
    • https://static.usrfiles.com/ugd/b8c837_dfe1d7760b8645cd8075260c6caec18d.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_off00006545.bin
92809dfcd2730f7860f293484bce8bc44729486f159126e10cabef72ca2bee7e
pdf-font-stream PDF embedded font (sfnt) at offset 0x6545 5104 bytes
font_01_sfnt_off00007691.bin
db51da7e0dd64b0e965e2d796d2bc3695f9115d48bc737a53def4950b4db8d52
pdf-font-stream PDF embedded font (sfnt) at offset 0x7691 10400 bytes