Malicious PDF — malware analysis report

Static analysis result for SHA-256 82f93b87ceac8e0a…

MALICIOUS

PDF

38.5 KB Created: 2020-08-13 12:51:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 5ffde23b8d2908b0ab09cb5e05e8be0f SHA-1: 9469ccd3a31747ffacb399852cbdadc64be701e4 SHA-256: 82f93b87ceac8e0aedd8c95ace16f64e081f8bb22473c1efb006af6dfd2673f3
120 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell T1204.002 Malicious Link

The PDF file contains numerous embedded links, with a critical heuristic identifying a link to a known malicious redirector at `https://ttraff.ru/wb?keyword=conjuguemos%20grammar%20worksheet%20ser%20vs%20estar%20answers`. The document body, though partially corrupted, also contains this URL and appears to be a lure disguised as a grammar worksheet. The presence of a link farm heuristic further suggests a malicious intent to distribute links, likely for SEO poisoning or to drive traffic to malicious sites.

Heuristics 3

  • 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.
  • 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/wb?keyword=conjuguemos%20grammar%20worksheet%20ser%20vs%20estar%20answers
    • http://files.jclandscapingandmasonry.com/uploads/1/3/2/6/132683137/82d8bf5.pdf
    • http://files.jngibson.com/uploads/1/3/1/4/131483830/15eebf4013975.pdf
    • http://tulivobeg.mattmanalo.com/uploads/1/3/1/1/131163599/32a7cf9b59a8.pdf
    • http://maselak.boylepublichealth.com/uploads/1/3/2/7/132711973/zetajazudede.pdf
    • http://nazafulel.patticarmen.com/uploads/1/3/0/7/130739625/dd75f59.pdf
    • https://cdn.shopify.com/s/files/1/0434/0760/5923/files/5160189195.pdf
    • https://cdn.shopify.com/s/files/1/0432/2246/6720/files/liwirarikasefawegonari.pdf
    • https://cdn.shopify.com/s/files/1/0431/8144/1181/files/41385550926.pdf
    • https://cdn.shopify.com/s/files/1/0429/3469/8147/files/bizhub_c224e_manual.pdf
    • https://cdn.shopify.com/s/files/1/0434/3287/0037/files/the_wiggles_splish_splash_big_red_boat.pdf
    • https://cdn.shopify.com/s/files/1/0429/1805/1996/files/cumulative_distribution_function_and_difference.pdf
    • https://cdn.shopify.com/s/files/1/0435/4228/2399/files/40360331684.pdf
    • https://cdn.shopify.com/s/files/1/0429/7120/1695/files/xerolix.pdf
    • https://cdn.shopify.com/s/files/1/0431/0165/1105/files/bajosuvufokivazekofibarap.pdf
    • https://cdn.shopify.com/s/files/1/0433/6487/6453/files/nuxezu.pdf
    • https://cdn.shopify.com/s/files/1/0430/9565/4567/files/labavufes.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/15796621189.pdf
    • https://cdn.shopify.com/s/files/1/0432/6519/6197/files/55072035321.pdf
    • https://cdn.shopify.com/s/files/1/0434/7373/1741/files/77730992349.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_off000054b5.bin
8708c73f7861ed83664b0ca43114c5851e6d93fd8f2f50353655d2fb687b2dda
pdf-font-stream PDF embedded font (sfnt) at offset 0x54B5 5264 bytes
font_01_sfnt_off00006690.bin
7a8adc9a7561bbc20f7500870c7b16fdf531c2c3a4eb8f16938cfcdd3b72c4a3
pdf-font-stream PDF embedded font (sfnt) at offset 0x6690 10796 bytes