Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef55e7d5281b5d2c…

MALICIOUS

PDF

35.3 KB Created: 2020-08-11 05:38:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 32446a42955e979fc3d370437c07f911 SHA-1: 3dcf7822d556e194588b33f4aeab3ee106a87680 SHA-256: ef55e7d5281b5d2c6e0c75d5035dfc59366ec26d94cff01a5869674d8461f340
152 Risk Score

Malware Insights

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

The PDF contains a mass external link farm, with many links pointing to benign Shopify URLs but one critical link to a known malicious redirector at 'ttraff.cc'. The document body, though heavily obfuscated, contains the same topic as the malicious URL, suggesting a lure to trick users into clicking the malicious link. The ML classifier strongly supports the malicious verdict.

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.cc/pify?keyword=difference+between+axial+and+centrifugal+compressor+pdf
    • http://files.versus.band/uploads/1/3/0/7/130738779/sasuweti-pawofi-jowuseliluvif.pdf
    • http://files.larnemusicfestival.com/uploads/1/3/1/6/131636601/pudixarerova.pdf
    • http://files.whitemetalres.com/uploads/1/3/0/8/130873983/1356508.pdf
    • https://cdn.shopify.com/s/files/1/0429/3695/9139/files/cat_3406e_service_manual.pdf
    • https://cdn.shopify.com/s/files/1/0429/8165/4691/files/wusogofuzasodoxi.pdf
    • https://cdn.shopify.com/s/files/1/0433/1008/8342/files/resmed_airsense_10_autoset_manual.pdf
    • https://cdn.shopify.com/s/files/1/0427/5381/8790/files/antonyms_and_synonyms_examples.pdf
    • https://cdn.shopify.com/s/files/1/0433/9515/4070/files/62315959865.pdf
    • https://cdn.shopify.com/s/files/1/0440/0067/3950/files/jimineruk.pdf
    • https://cdn.shopify.com/s/files/1/0437/6081/2189/files/60197472781.pdf
    • https://cdn.shopify.com/s/files/1/0437/3810/3962/files/72787994166.pdf
    • https://cdn.shopify.com/s/files/1/0429/0058/6649/files/10974758817.pdf
    • https://cdn.shopify.com/s/files/1/0431/2567/0037/files/monusewamotudopup.pdf
    • https://cdn.shopify.com/s/files/1/0429/2060/7900/files/91916206521.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_off00004bf9.bin
3c58586a09eebbf7dcd7d308586b855facafa4b619305016b42d379514e6c68a
pdf-font-stream PDF embedded font (sfnt) at offset 0x4BF9 5772 bytes
font_01_sfnt_off00005f93.bin
86a294634889e183130cd1ed145326f1922df8a37fcbe1f19e7c4d445c5158e7
pdf-font-stream PDF embedded font (sfnt) at offset 0x5F93 9584 bytes