Malicious PDF — malware analysis report

Static analysis result for SHA-256 da1bf25335da3c4f…

MALICIOUS

PDF

42.7 KB Created: 2020-09-02 00:49:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c4eddbe70a1476c7dea9833e0a5efb6d SHA-1: 5637b1e9ef4c3db0d7557cf3fad87793f5ec5d1c SHA-256: da1bf25335da3c4f4bd26af84dfcbd6598af85c1af57825118cb2ac96de1470e
152 Risk Score

Malware Insights

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

The PDF contains embedded links, one of which points to a known malicious redirector. The document body, though heavily obfuscated, contains text that appears to be a lure for 'Clarke county iowa sheriff report'. The presence of a large number of external PDF links, many hosted on cdn.shopify.com, suggests a link farm used for SEO poisoning or to distribute further malicious 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/wix?keyword=clarke+county+iowa+sheriff+report
    • https://static.usrfiles.com/ugd/3de8a6_5a516d6fa52f4cd8a76c59afc2fe75ad.pdf
    • https://static.usrfiles.com/ugd/822ecd_34f4824195a948f2b59f7e27c825e1de.pdf
    • https://static.usrfiles.com/ugd/234f58_da6a7e1a64bc491983ccd414e46b7fb5.pdf
    • https://static.usrfiles.com/ugd/43d598_a4831557b9654217b930a994ad0e6e0c.pdf
    • https://static.usrfiles.com/ugd/4725f1_2261902ac14f4aaba143987891c7c2ae.pdf
    • https://static.usrfiles.com/ugd/6cabbb_88d9a64d1ac54bc182f32f40933073a9.pdf
    • https://static.usrfiles.com/ugd/921909_529de54c1d924833a156d52c1eb5710b.pdf
    • https://cdn.shopify.com/s/files/1/0437/8345/4871/files/best_telugu_hd_movies_site.pdf
    • https://cdn.shopify.com/s/files/1/0429/7805/0201/files/mezatikinasixuleteveget.pdf
    • https://cdn.shopify.com/s/files/1/0431/7279/0428/files/4166223174.pdf
    • https://cdn.shopify.com/s/files/1/0431/0266/6914/files/43397122444.pdf
    • https://cdn.shopify.com/s/files/1/0438/8601/8712/files/best_pickaxe_enchantments.pdf
    • https://cdn.shopify.com/s/files/1/0431/0997/4169/files/prefix_and_suffix_lesson_plan.pdf
    • https://cdn.shopify.com/s/files/1/0433/8620/8406/files/75379708296.pdf
    • https://cdn.shopify.com/s/files/1/0437/0907/1513/files/tamilrockers_2018_movies_telugu_free.pdf
    • https://cdn.shopify.com/s/files/1/0428/2672/7580/files/it_builds_character_5e.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_off00006928.bin
18f32a05c82cdbdb05bc9aba632c08d35eebd5f0f53e6206ab14ccb611afa47c
pdf-font-stream PDF embedded font (sfnt) at offset 0x6928 5268 bytes
font_01_sfnt_off00007b29.bin
e292582928462bae273e0d75b7869c94a4efce612900d0400f23559632366557
pdf-font-stream PDF embedded font (sfnt) at offset 0x7B29 10112 bytes